Wireless Earbud Charging

ABSTRACT

Examples described herein relate to a charging system for wireless earbuds involving charging adapters that are attachable to the wireless earbuds. In some implementations, the charging adapter is attachable to an external surface of an earbud using a magnetic or mechanical interface that align electrodes of the charging adapter with electrodes on the wireless headset, allowing an internal battery of the earbud to draw current and charge from the charging adapter while the earbud is in-ear. Then, when the internal battery is and recharged using a charging case or wall charger, the charging adapter can be detached from the earbud.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119 of U.S.provisional Patent Application No. 62/867,938, filed on Jun. 28, 2019,entitled “Wireless Earbud Charging,” which is incorporated herein byreference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure is related to consumer goods and, moreparticularly, to methods, systems, products, features, services, andother elements directed to media playback or some aspect thereof.

BACKGROUND

Options for accessing and listening to digital audio in an out-loudsetting were limited until in 2002, when SONOS, Inc. began developmentof a new type of playback system. Sonos then filed one of its firstpatent applications in 2003, entitled “Method for Synchronizing AudioPlayback between Multiple Networked Devices,” and began offering itsfirst media playback systems for sale in 2005. The Sonos Wireless HomeSound System enables people to experience music from many sources viaone or more networked playback devices. Through a software controlapplication installed on a controller (e.g., smartphone, tablet,computer, voice input device), one can play what she wants in any roomhaving a networked playback device. Media content (e.g., songs,podcasts, video sound) can be streamed to playback devices such thateach room with a playback device can play back corresponding differentmedia content. In addition, rooms can be grouped together forsynchronous playback of the same media content, and/or the same mediacontent can be heard in all rooms synchronously.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects, and advantages of the presently disclosed technologymay be better understood with regard to the following description,appended claims, and accompanying drawings, as listed below. A personskilled in the relevant art will understand that the features shown inthe drawings are for purposes of illustrations, and variations,including different and/or additional features and arrangements thereof,are possible.

FIG. 1A is a partial cutaway view of an environment having a mediaplayback system configured in accordance with aspects of the disclosedtechnology.

FIG. 1B is a schematic diagram of the media playback system of FIG. 1Aand one or more networks.

FIG. 1C is a block diagram of a playback device.

FIG. 1D is a block diagram of a playback device.

FIG. 1E is a block diagram of a network microphone device.

FIG. 1F is a block diagram of a network microphone device.

FIG. 1G is a block diagram of a playback device.

FIG. 1H is a partially schematic diagram of a control device.

FIG. 2A is a block diagram of an earbud configured in accordance withaspects of the disclosed technology.

FIG. 2B is a side partial cutaway view of the earbud configured inaccordance with aspects of the disclosed technology.

FIG. 3A is a side partial cutaway view of a charging adapter configuredin accordance with aspects of the disclosed technology.

FIG. 3B is a side partial cutaway view of the earbud and the chargingadapter configured in accordance with aspects of the disclosedtechnology.

FIG. 3C is another side partial cutaway view of the earbud and thecharging adapter configured in accordance with aspects of the disclosedtechnology.

FIG. 4 is a side partial cutaway view of a charging case configured inaccordance with aspects of the disclosed technology.

FIG. 5A is a side partial cutaway view of a pair of earbuds, chargingadapters, and a charging case configured in accordance with aspects ofthe disclosed technology.

FIG. 5B is another side partial cutaway view of a pair of earbuds,charging adapters, and a charging case configured in accordance withaspects of the disclosed technology.

FIG. 5C is another side partial cutaway view of a pair of earbuds,charging adapters, and a charging case configured in accordance withaspects of the disclosed technology.

FIG. 5D is another side partial cutaway view of a pair of earbuds,charging adapters, and a charging case configured in accordance withaspects of the disclosed technology.

FIG. 6A is a side partial cutaway view of a pair of earbuds, chargingadapters, and a charging case configured in accordance with aspects ofthe disclosed technology.

FIG. 6B is a side partial cutaway view of a pair of earbuds, chargingadapters, and a charging case configured in accordance with aspects ofthe disclosed technology.

FIG. 7 is a flow diagram illustrating an example method to facilitatecharging of one or more wireless earbuds in accordance with aspects ofthe disclosed technology.

FIG. 8A is a front isometric view of earbuds configured in accordancewith aspects of the disclosed technology.

FIG. 8B is a bottom view of a charging case configured in accordancewith aspects of the disclosed technology.

FIG. 8C is a top view of the charging case.

FIG. 8D is a first side view of the charging case.

FIG. 8E is a second side view of the charging case.

FIG. 8F is a front isometric view of earbuds illustrating exemplaryarrangement with the charging case.

FIG. 8G is an isometric view of the earbud.

FIG. 8H is a first side view of the earbud.

FIG. 8I is a second side view of the earbud.

FIG. 8J is a third side view of the earbud.

FIG. 8K is a fourth side view of the earbud.

FIG. 8L is a fifth side view of the earbud.

FIG. 8M is a sixth side view of the earbud.

FIG. 9A is a front view of headphones configured in accordance withaspects of the disclosed technology.

FIG. 9B is a first side view of the headphones.

FIG. 9C is a second side view of the headphones.

The drawings are for the purpose of illustrating example embodiments,but those of ordinary skill in the art will understand that thetechnology disclosed herein is not limited to the arrangements and/orinstrumentality shown in the drawings.

DETAILED DESCRIPTION I. Overview

Examples described herein relate to a charging system for wirelessearbuds involving charging adapters that are attachable to the wirelessearbuds. Wireless earbuds generally have limited play time due to sizeand weight requirements for comfortable use in-ear. Some wirelessearbuds include one or more case batteries in a charging case, so thatwhen the internal batteries of the wireless earbuds are depleted, theycan be put into the charging case and recharged using the casebatteries. While such a charging case allows wireless earbuds to berecharged away from wall power, one problem with this implementation isthat the wireless earbuds cannot be used while they are being rechargedin the charging case.

Other workarounds for limited play time of wireless earbuds exist aswell. For instance, some users will charge one earbud while listeningwith the other one; the disadvantages of this approach include loss ofstereo sound, as well as the additional attention required for switchingbetween the earbuds. Some wireless earbuds support quick charging, suchthat 15 minutes of charging provides 1-2 hours of playtime; thisapproach, like the charging case, is disruptive to playback. Yetfurther, other wireless earbuds include a detectable neckband with anextra battery. This implementation is cumbersome and affects usability.

As noted above, example implementations described herein involve acharging adapter that includes one or more batteries (referred to hereinas “adapter batteries”). In some implementations, the charging adapteris attachable to an external surface of an earbud using a magnetic ormechanical interface that align electrodes of the charging adapter withelectrodes on the wireless headset, allowing an internal battery of theearbud to draw current and charge from the charging adapter while theearbud is in-ear. Then, when the internal battery is and recharged usinga charging case or wall charger, the charging adapter can be detachedfrom the earbud.

Given such charging adapters, example systems may include a chargingcase configured to charge the charging adapters independently of orconcurrently with the earbuds. For instance, a charging case may includefirst and second volumes shaped to carry a first earbud and a secondearbud while attached to a first charging adapter and a second chargingadapter, respectively. Further, the charging case may be configured tocarry the earbuds and charging adapters in such a manner that electrodesin the charging case, the charging adapters, and the earbuds align sothat the charging case charges the charging adapters, which in turncharge the earbuds. Alternatively, the charging case may includeseparate volumes configured to carry a left earbud, a right earbud, anda first and second charging adapter.

In such implementations, the earbuds can be considered as operating inone of three different modes. In a first (“normal”) mode, the earbudsare in-ear for playback, while the charging adapters are in the chargingcase being charged. In a second (“active charging”) mode, the chargingadapters are attached to the earbuds and charging the earbuds while theearbuds are in operation. In a third (“passive charging”) mode, thecharging adapters are attached to the earbuds and carried in thecharging case. While in the passive charging mode, the charging casecharges both the charging adapters and the earbuds, either independentlyor via attachment. If the charging case is disconnected from wall power,case batteries in the charging case charge the carried charging adaptersand/or earbuds, until depleted. If the charging case is connected towall power, the charging case charges its case batteries in addition tothe charging adapters and the earbuds.

As noted above, example techniques described herein involve a system forwireless earbud charging. An example system includes a pair of earbudsincluding a first earbud and a second earbud, a first and secondcharging adapter comprising one or more respective charging batteries,and a charging case.

The first earbud includes a first IEEE 802.15-compatible interface, afirst internal battery, a first audio driver, a housing carrying thefirst IEEE 802.15-compatible interface and the first internal battery.The housing of the first earbud comprises a first portion insertableinto a first ear canal, the first portion carrying the first audiodriver and a second portion carrying a magnetic interface that includesone or more magnets that (i) attach the first charging adapterexternally to the housing of the first earbud and (ii) align electrodesof the first charging adapter to electrodes of the magnetic interface.The first earbud further includes a first controller carried in thehousing of the first earbud and configured to perform functionscomprising detecting attachment of the first charging adapter to themagnetic interface and based on detecting that the first chargingadapter is attached to the magnetic interface, causing the firstinternal battery to charge from the first charging adapter. Charging thefirst internal battery comprises drawing current from the one or moreadapter batteries of the first charging adapter via the electrodes ofthe magnetic connection interface and the electrodes of the firstcharging adapter. The second earbud is similar to the first earbud.

While some examples described herein may refer to functions performed bygiven actors such as “users,” “listeners,” and/or other entities, itshould be understood that this is for purposes of explanation only. Theclaims should not be interpreted to require action by any such exampleactor unless explicitly required by the language of the claimsthemselves.

Moreover, some functions are described herein as being performed “basedon” or “in response to” another element or function. “Based on” shouldbe understood that one element or function is related to anotherfunction or element. “In response to” should be understood that oneelement or function is a necessary result of another function orelement. For the sake of brevity, functions are generally described asbeing based on another function when a functional link exists; however,such disclosure should be understood as disclosing either type offunctional relationship.

In the Figures, identical reference numbers identify generally similar,and/or identical, elements. To facilitate the discussion of anyparticular element, the most significant digit or digits of a referencenumber refers to the Figure in which that element is first introduced.For example, element 110 a is first introduced and discussed withreference to FIG. 1A. Many of the details, dimensions, angles and otherfeatures shown in the Figures are merely illustrative of particularembodiments of the disclosed technology. Accordingly, other embodimentscan have other details, dimensions, angles and features withoutdeparting from the spirit or scope of the disclosure. In addition, thoseof ordinary skill in the art will appreciate that further embodiments ofthe various disclosed technologies can be practiced without several ofthe details described below.

II. Suitable Operating Environment

FIG. 1A is a partial cutaway view of a media playback system 100distributed in an environment 101 (e.g., a house). The media playbacksystem 100 includes one or more playback devices 110 (identifiedindividually as playback devices 110 a-n), one or more networkmicrophone devices (“NMDs”), 120 (identified individually as NMDs 120a-c), and one or more control devices 130 (identified individually ascontrol devices 130 a and 130 b).

As used herein the term “playback device” can generally refer to anetwork device configured to receive, process, and output data of amedia playback system. For example, a playback device can be a networkdevice that receives and processes audio content. In some embodiments, aplayback device includes one or more transducers or speakers powered byone or more amplifiers. In other embodiments, however, a playback deviceincludes one of (or neither of) the speaker and the amplifier. Forinstance, a playback device can comprise one or more amplifiersconfigured to drive one or more speakers external to the playback devicevia a corresponding wire or cable.

Moreover, as used herein the term NMD (i.e., a “network microphonedevice”) can generally refer to a network device that is configured foraudio detection. In some embodiments, an NMD is a stand-alone deviceconfigured primarily for audio detection. In other embodiments, an NMDis incorporated into a playback device (or vice versa).

The term “control device” can generally refer to a network deviceconfigured to perform functions relevant to facilitating user access,control, and/or configuration of the media playback system 100.

Each of the playback devices 110 is configured to receive audio signalsor data from one or more media sources (e.g., one or more remoteservers, one or more local devices) and play back the received audiosignals or data as sound. The one or more NMDs 120 are configured toreceive spoken word commands, and the one or more control devices 130are configured to receive user input. In response to the received spokenword commands and/or user input, the media playback system 100 can playback audio via one or more of the playback devices 110. In certainembodiments, the playback devices 110 are configured to commenceplayback of media content in response to a trigger. For instance, one ormore of the playback devices 110 can be configured to play back amorning playlist upon detection of an associated trigger condition(e.g., presence of a user in a kitchen, detection of a coffee machineoperation). In some embodiments, for example, the media playback system100 is configured to play back audio from a first playback device (e.g.,the playback device 100 a) in synchrony with a second playback device(e.g., the playback device 100 b). Interactions between the playbackdevices 110, NMDs 120, and/or control devices 130 of the media playbacksystem 100 configured in accordance with the various embodiments of thedisclosure are described in greater detail below with respect to FIGS.1B-6.

In the illustrated embodiment of FIG. 1A, the environment 101 includes ahousehold having several rooms, spaces, and/or playback zones, including(clockwise from upper left) a master bathroom 101 a, a master bedroom101 b, a second bedroom 101 c, a family room or den 101 d, an office 101e, a living room 101 f, a dining room 101 g, a kitchen 101 h, and anoutdoor patio 101 i. While certain embodiments and examples aredescribed below in the context of a home environment, the technologiesdescribed herein may be implemented in other types of environments. Insome embodiments, for example, the media playback system 100 can beimplemented in one or more commercial settings (e.g., a restaurant,mall, airport, hotel, a retail or other store), one or more vehicles(e.g., a sports utility vehicle, bus, car, a ship, a boat, an airplane),multiple environments (e.g., a combination of home and vehicleenvironments), and/or another suitable environment where multi-zoneaudio may be desirable.

The media playback system 100 can comprise one or more playback zones,some of which may correspond to the rooms in the environment 101. Themedia playback system 100 can be established with one or more playbackzones, after which additional zones may be added, or removed to form,for example, the configuration shown in FIG. 1A. Each zone may be givena name according to a different room or space such as the office 101 e,master bathroom 101 a, master bedroom 101 b, the second bedroom 101 c,kitchen 101 h, dining room 101 g, living room 101 f, and/or the balcony101 i. In some aspects, a single playback zone may include multiplerooms or spaces. In certain aspects, a single room or space may includemultiple playback zones.

In the illustrated embodiment of FIG. 1A, the master bathroom 101 a, thesecond bedroom 101 c, the office 101 e, the living room 101 f, thedining room 101 g, the kitchen 101 h, and the outdoor patio 101 i eachinclude one playback device 110, and the master bedroom 101 b and theden 101 d include a plurality of playback devices 110. In the masterbedroom 101 b, the playback devices 110 l and 110 m may be configured,for example, to play back audio content in synchrony as individual onesof playback devices 110, as a bonded playback zone, as a consolidatedplayback device, and/or any combination thereof. Similarly, in the den101 d, the playback devices 110 h -j can be configured, for instance, toplay back audio content in synchrony as individual ones of playbackdevices 110, as one or more bonded playback devices, and/or as one ormore consolidated playback devices. Additional details regarding bondedand consolidated playback devices are described below with respect toFIGS. 1B and 1E.

In some aspects, one or more of the playback zones in the environment101 may each be playing different audio content. For instance, a usermay be grilling on the patio 101 i and listening to hip hop music beingplayed by the playback device 110 c while another user is preparing foodin the kitchen 101 h and listening to classical music played by theplayback device 110 b. In another example, a playback zone may play thesame audio content in synchrony with another playback zone. Forinstance, the user may be in the office 101 e listening to the playbackdevice 110 f playing back the same hip hop music being played back byplayback device 110 c on the patio 101 i. In some aspects, the playbackdevices 110 c and 110 f play back the hip hop music in synchrony suchthat the user perceives that the audio content is being playedseamlessly (or at least substantially seamlessly) while moving betweendifferent playback zones.

Example synchrony techniques involve a group coordinator providing audiocontent and timing information to one or more group members tofacilitate synchronous playback among the group coordinator and thegroup members. Additional details regarding audio playbacksynchronization among playback devices and/or zones can be found, forexample, in U.S. Pat. No. 8,234,395 entitled, “System and method forsynchronizing operations among a plurality of independently clockeddigital data processing devices,” which is incorporated herein byreference in its entirety.

a. Suitable Media Playback System

FIG. 1B is a schematic diagram of the media playback system 100 and acloud network 102. For ease of illustration, certain devices of themedia playback system 100 and the cloud network 102 are omitted fromFIG. 1B. One or more communication links 103 (referred to hereinafter as“the links 103”) communicatively couple the media playback system 100and the cloud network 102.

The links 103 can comprise, for example, one or more wired networks, oneor more wireless networks, one or more wide area networks (WAN), one ormore local area networks (LAN), one or more personal area networks(PAN), one or more telecommunication networks (e.g., one or more GlobalSystem for Mobiles (GSM) networks, Code Division Multiple Access (CDMA)networks, Long-Term Evolution (LTE) networks, 5G communication networknetworks, and/or other suitable data transmission protocol networks),etc. The cloud network 102 is configured to deliver media content (e.g.,audio content, video content, photographs, social media content) to themedia playback system 100 in response to a request transmitted from themedia playback system 100 via the links 103. In some embodiments, thecloud network 102 is further configured to receive data (e.g. voiceinput data) from the media playback system 100 and correspondinglytransmit commands and/or media content to the media playback system 100.

The cloud network 102 includes computing devices 106 (identifiedseparately as a first computing device 106 a, a second computing device106 b, and a third computing device 106 c). The computing devices 106can comprise individual computers or servers, such as, for example, amedia streaming service server storing audio and/or other media content,a voice service server, a social media server, a media playback systemcontrol server, etc. In some embodiments, one or more of the computingdevices 106 comprise modules of a single computer or server. In certainembodiments, one or more of the computing devices 106 comprise one ormore modules, computers, and/or servers. Moreover, while the cloudnetwork 102 is described above in the context of a single cloud network,in some embodiments the cloud network 102 includes a plurality of cloudnetworks comprising communicatively coupled computing devices.Furthermore, while the cloud network 102 is shown in FIG. 1B as havingthree of the computing devices 106, in some embodiments, the cloudnetwork 102 includes fewer (or more than) three computing devices 106.

The media playback system 100 is configured to receive media contentfrom the networks 102 via the links 103. The received media content cancomprise, for example, a Uniform Resource Identifier (URI) and/or aUniform Resource Locator (URL). For instance, in some examples, themedia playback system 100 can stream, download, or otherwise obtain datafrom a URI or a URL corresponding to the received media content. Anetwork 104 communicatively couples the links 103 and at least a portionof the devices (e.g., one or more of the playback devices 110, NMDs 120,and/or control devices 130) of the media playback system 100. Thenetwork 104 can include, for example, a wireless network (e.g., a WiFinetwork, a Bluetooth, a Z-Wave network, a ZigBee, and/or other suitablewireless communication protocol network) and/or a wired network (e.g., anetwork comprising Ethernet, Universal Serial Bus (USB), and/or anothersuitable wired communication). As those of ordinary skill in the artwill appreciate, as used herein, “WiFi” can refer to several differentcommunication protocols including, for example, Institute of Electricaland Electronics Engineers (IEEE) 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, 802.11ac, 802.11ad, 802.11af, 802.11ah, 802.11ai, 802.11aj,802.11aq, 802.11ax, 802.11ay, 802.15, etc. transmitted at 2.4 Gigahertz(GHz), 5 GHz, and/or another suitable frequency.

In some embodiments, the network 104 includes a dedicated communicationnetwork that the media playback system 100 uses to transmit messagesbetween individual devices and/or to transmit media content to and frommedia content sources (e.g., one or more of the computing devices 106).In certain embodiments, the network 104 is configured to be accessibleonly to devices in the media playback system 100, thereby reducinginterference and competition with other household devices. In otherembodiments, however, the network 104 includes an existing householdcommunication network (e.g., a household WiFi network). In someembodiments, the links 103 and the network 104 comprise one or more ofthe same networks. In some aspects, for example, the links 103 and thenetwork 104 comprise a telecommunication network (e.g., an LTE network,a 5G network). Moreover, in some embodiments, the media playback system100 is implemented without the network 104, and devices comprising themedia playback system 100 can communicate with each other, for example,via one or more direct connections, PANs, telecommunication networks,and/or other suitable communication links.

In some embodiments, audio content sources may be regularly added orremoved from the media playback system 100. In some embodiments, forexample, the media playback system 100 performs an indexing of mediaitems when one or more media content sources are updated, added to,and/or removed from the media playback system 100. The media playbacksystem 100 can scan identifiable media items in some or all foldersand/or directories accessible to the playback devices 110, and generateor update a media content database comprising metadata (e.g., title,artist, album, track length) and other associated information (e.g.,URIs, URLs) for each identifiable media item found. In some embodiments,for example, the media content database is stored on one or more of theplayback devices 110, network microphone devices 120, and/or controldevices 130.

In the illustrated embodiment of FIG. 1B, the playback devices 110 l and110 m comprise a group 107 a. The playback devices 110 l and 110 m canbe positioned in different rooms in a household and be grouped togetherin the group 107 a on a temporary or permanent basis based on user inputreceived at the control device 130 a and/or another control device 130in the media playback system 100. When arranged in the group 107 a, theplayback devices 110 l and 110 m can be configured to play back the sameor similar audio content in synchrony from one or more audio contentsources. In certain embodiments, for example, the group 107 a includes abonded zone in which the playback devices 110 l and 110 m comprise leftaudio and right audio channels, respectively, of multi-channel audiocontent, thereby producing or enhancing a stereo effect of the audiocontent. In some embodiments, the group 107 a includes additionalplayback devices 110. In other embodiments, however, the media playbacksystem 100 omits the group 107 a and/or other grouped arrangements ofthe playback devices 110.

The media playback system 100 includes the NMDs 120 a and 120 d, eachcomprising one or more microphones configured to receive voiceutterances from a user. In the illustrated embodiment of FIG. 1B, theNMD 120 a is a standalone device and the NMD 120 d is integrated intothe playback device 110 n. The NMD 120 a, for example, is configured toreceive voice input 121 from a user 123. In some embodiments, the NMD120 a transmits data associated with the received voice input 121 to avoice assistant service (VAS) configured to (i) process the receivedvoice input data and (ii) transmit a corresponding command to the mediaplayback system 100. In some aspects, for example, the computing device106 c includes one or more modules and/or servers of a VAS (e.g., a VASoperated by one or more of SONOS®, AMAZON®, GOOGLE® APPLE®, MICROSOFT®).The computing device 106 c can receive the voice input data from the NMD120 a via the network 104 and the links 103. In response to receivingthe voice input data, the computing device 106 c processes the voiceinput data (i.e., “Play Hey Jude by The Beatles”), and determines thatthe processed voice input includes a command to play a song (e.g., “HeyJude”). The computing device 106 c accordingly transmits commands to themedia playback system 100 to play back “Hey Jude” by the Beatles from asuitable media service (e.g., via one or more of the computing devices106) on one or more of the playback devices 110.

b. Suitable Playback Devices

FIG. 1C is a block diagram of the playback device 110 a comprising aninput/output 111. The input/output 111 can include an analog I/O 111 a(e.g., one or more wires, cables, and/or other suitable communicationlinks configured to carry analog signals) and/or a digital I/O 111 b(e.g., one or more wires, cables, or other suitable communication linksconfigured to carry digital signals). In some embodiments, the analogI/O 111 a is an audio line-in input connection comprising, for example,an auto-detecting 3.5 mm audio line-in connection. In some embodiments,the digital I/O 111 b includes a Sony/Philips Digital Interface Format(S/PDIF) communication interface and/or cable and/or a Toshiba Link(TOSLINK) cable. In some embodiments, the digital I/O 111 b includes anHigh-Definition Multimedia Interface (HDMI) interface and/or cable. Insome embodiments, the digital I/O 111 b includes one or more wirelesscommunication links comprising, for example, a radio frequency (RF),infrared, WiFi, Bluetooth, or another suitable communication protocol.In certain embodiments, the analog I/O 111 a and the digital 111 bcomprise interfaces (e.g., ports, plugs, jacks) configured to receiveconnectors of cables transmitting analog and digital signals,respectively, without necessarily including cables.

The playback device 110 a, for example, can receive media content (e.g.,audio content comprising music and/or other sounds) from a local audiosource 105 via the input/output 111 (e.g., a cable, a wire, a PAN, aBluetooth connection, an ad hoc wired or wireless communication network,and/or another suitable communication link). The local audio source 105can comprise, for example, a mobile device (e.g., a smartphone, atablet, a laptop computer) or another suitable audio component (e.g., atelevision, a desktop computer, an amplifier, a phonograph, a Blu-rayplayer, a memory storing digital media files). In some aspects, thelocal audio source 105 includes local music libraries on a smartphone, acomputer, a networked-attached storage (NAS), and/or another suitabledevice configured to store media files. In certain embodiments, one ormore of the playback devices 110, NMDs 120, and/or control devices 130comprise the local audio source 105. In other embodiments, however, themedia playback system omits the local audio source 105 altogether. Insome embodiments, the playback device 110 a does not include aninput/output 111 and receives all audio content via the network 104.

The playback device 110 a further includes electronics 112, a userinterface 113 (e.g., one or more buttons, knobs, dials, touch-sensitivesurfaces, displays, touchscreens), and one or more transducers 114(referred to hereinafter as “the transducers 114”). The electronics 112is configured to receive audio from an audio source (e.g., the localaudio source 105) via the input/output 111, one or more of the computingdevices 106 a-c via the network 104 (FIG. 1B)), amplify the receivedaudio, and output the amplified audio for playback via one or more ofthe transducers 114. In some embodiments, the playback device 110 aoptionally includes one or more microphones 115 (e.g., a singlemicrophone, a plurality of microphones, a microphone array) (hereinafterreferred to as “the microphones 115”). In certain embodiments, forexample, the playback device 110 a having one or more of the optionalmicrophones 115 can operate as an NMD configured to receive voice inputfrom a user and correspondingly perform one or more operations based onthe received voice input.

In the illustrated embodiment of FIG. 1C, the electronics 112 compriseone or more processors 112 a (referred to hereinafter as “the processors112 a”), memory 112 b, software components 112 c, a network interface112 d, one or more audio processing components 112 g (referred tohereinafter as “the audio components 112 g”), one or more audioamplifiers 112 h (referred to hereinafter as “the amplifiers 112 h”),and power 112 i (e.g., one or more power supplies, power cables, powerreceptacles, batteries, induction coils, Power-over Ethernet (POE)interfaces, and/or other suitable sources of electric power). In someembodiments, the electronics 112 optionally include one or more othercomponents 112 j (e.g., one or more sensors, video displays,touchscreens).

The processors 112 a can comprise clock-driven computing component(s)configured to process data, and the memory 112 b can comprise acomputer-readable medium (e.g., a tangible, non-transitorycomputer-readable medium, data storage loaded with one or more of thesoftware components 112 c) configured to store instructions forperforming various operations and/or functions. The processors 112 a areconfigured to execute the instructions stored on the memory 112 b toperform one or more of the operations. The operations can include, forexample, causing the playback device 110 a to retrieve audio data froman audio source (e.g., one or more of the computing devices 106 a-c(FIG. 1B)), and/or another one of the playback devices 110. In someembodiments, the operations further include causing the playback device110 a to send audio data to another one of the playback devices 110 aand/or another device (e.g., one of the NMDs 120). Certain embodimentsinclude operations causing the playback device 110 a to pair withanother of the one or more playback devices 110 to enable amulti-channel audio environment (e.g., a stereo pair, a bonded zone).

The processors 112 a can be further configured to perform operationscausing the playback device 110 a to synchronize playback of audiocontent with another of the one or more playback devices 110. As thoseof ordinary skill in the art will appreciate, during synchronousplayback of audio content on a plurality of playback devices, a listenerwill preferably be unable to perceive time-delay differences betweenplayback of the audio content by the playback device 110 a and the otherone or more other playback devices 110. Additional details regardingaudio playback synchronization among playback devices can be found, forexample, in U.S. Pat. No. 8,234,395, which was incorporated by referenceabove.

In some embodiments, the memory 112 b is further configured to storedata associated with the playback device 110 a, such as one or morezones and/or zone groups of which the playback device 110 a is a member,audio sources accessible to the playback device 110 a, and/or a playbackqueue that the playback device 110 a (and/or another of the one or moreplayback devices) can be associated with. The stored data can compriseone or more state variables that are periodically updated and used todescribe a state of the playback device 110 a. The memory 112 b can alsoinclude data associated with a state of one or more of the other devices(e.g., the playback devices 110, NMDs 120, control devices 130) of themedia playback system 100. In some aspects, for example, the state datais shared during predetermined intervals of time (e.g., every 5 seconds,every 10 seconds, every 60 seconds) among at least a portion of thedevices of the media playback system 100, so that one or more of thedevices have the most recent data associated with the media playbacksystem 100.

The network interface 112 d is configured to facilitate a transmissionof data between the playback device 110 a and one or more other deviceson a data network such as, for example, the links 103 and/or the network104 (FIG. 1B). The network interface 112 d is configured to transmit andreceive data corresponding to media content (e.g., audio content, videocontent, text, photographs) and other signals (e.g., non-transitorysignals) comprising digital packet data including an Internet Protocol(IP)-based source address and/or an IP-based destination address. Thenetwork interface 112 d can parse the digital packet data such that theelectronics 112 properly receives and processes the data destined forthe playback device 110 a.

In the illustrated embodiment of FIG. 1C, the network interface 112 dincludes one or more wireless interfaces 112 e (referred to hereinafteras “the wireless interface 112 e”). The wireless interface 112 e (e.g.,a suitable interface comprising one or more antennae) can be configuredto wirelessly communicate with one or more other devices (e.g., one ormore of the other playback devices 110, NMDs 120, and/or control devices130) that are communicatively coupled to the network 104 (FIG. 1B) inaccordance with a suitable wireless communication protocol (e.g., WiFi,Bluetooth, LTE). In some embodiments, the network interface 112 doptionally includes a wired interface 112 f (e.g., an interface orreceptacle configured to receive a network cable such as an Ethernet, aUSB-A, USB-C, and/or Thunderbolt cable) configured to communicate over awired connection with other devices in accordance with a suitable wiredcommunication protocol. In certain embodiments, the network interface112 d includes the wired interface 112 f and excludes the wirelessinterface 112 e. In some embodiments, the electronics 112 excludes thenetwork interface 112 d altogether and transmits and receives mediacontent and/or other data via another communication path (e.g., theinput/output 111).

The audio components 112 g are configured to process and/or filter datacomprising media content received by the electronics 112 (e.g., via theinput/output 111 and/or the network interface 112 d) to produce outputaudio signals. In some embodiments, the audio processing components 112g comprise, for example, one or more digital-to-analog converters (DAC),audio preprocessing components, audio enhancement components, a digitalsignal processors (DSPs), and/or other suitable audio processingcomponents, modules, circuits, etc. In certain embodiments, one or moreof the audio processing components 112 g can comprise one or moresubcomponents of the processors 112 a. In some embodiments, theelectronics 112 omits the audio processing components 112 g. In someaspects, for example, the processors 112 a execute instructions storedon the memory 112 b to perform audio processing operations to producethe output audio signals.

The amplifiers 112 h are configured to receive and amplify the audiooutput signals produced by the audio processing components 112 g and/orthe processors 112 a. The amplifiers 112 h can comprise electronicdevices and/or components configured to amplify audio signals to levelssufficient for driving one or more of the transducers 114. In someembodiments, for example, the amplifiers 112 h include one or moreswitching or class-D power amplifiers. In other embodiments, however,the amplifiers include one or more other types of power amplifiers(e.g., linear gain power amplifiers, class-A amplifiers, class-Bamplifiers, class-AB amplifiers, class-C amplifiers, class-D amplifiers,class-E amplifiers, class-F amplifiers, class-G and/or class Hamplifiers, and/or another suitable type of power amplifier). In certainembodiments, the amplifiers 112 h comprise a suitable combination of twoor more of the foregoing types of power amplifiers. Moreover, in someembodiments, individual ones of the amplifiers 112 h correspond toindividual ones of the transducers 114. In other embodiments, however,the electronics 112 includes a single one of the amplifiers 112 hconfigured to output amplified audio signals to a plurality of thetransducers 114. In some other embodiments, the electronics 112 omitsthe amplifiers 112 h.

The transducers 114 (e.g., one or more speakers and/or speaker drivers)receive the amplified audio signals from the amplifier 112 h and renderor output the amplified audio signals as sound (e.g., audible soundwaves having a frequency between about 20 Hertz (Hz) and 20 kilohertz(kHz)). In some embodiments, the transducers 114 can comprise a singletransducer. In other embodiments, however, the transducers 114 comprisea plurality of audio transducers. In some embodiments, the transducers114 comprise more than one type of transducer. For example, thetransducers 114 can include one or more low frequency transducers (e.g.,subwoofers, woofers), mid-range frequency transducers (e.g., mid-rangetransducers, mid-woofers), and one or more high frequency transducers(e.g., one or more tweeters). As used herein, “low frequency” cangenerally refer to audible frequencies below about 500 Hz, “mid-rangefrequency” can generally refer to audible frequencies between about 500Hz and about 2 kHz, and “high frequency” can generally refer to audiblefrequencies above 2 kHz. In certain embodiments, however, one or more ofthe transducers 114 comprise transducers that do not adhere to theforegoing frequency ranges. For example, one of the transducers 114 maycomprise a mid-woofer transducer configured to output sound atfrequencies between about 200 Hz and about 5 kHz.

By way of illustration, SONOS, Inc. presently offers (or has offered)for sale certain playback devices including, for example, a “SONOS ONE,”“PLAY:1,” “PLAY:3,” “PLAY:5,” “PLAYBAR,” “PLAYBASE,” “CONNECT:AMP,”“CONNECT,” and “SUB.” Other suitable playback devices may additionallyor alternatively be used to implement the playback devices of exampleembodiments disclosed herein. Additionally, one of ordinary skilled inthe art will appreciate that a playback device is not limited to theexamples described herein or to SONOS product offerings. In someembodiments, for example, one or more playback devices 110 includeswired or wireless headphones (e.g., over-the-ear headphones, on-earheadphones, in-ear earphones). In other embodiments, one or more of theplayback devices 110 comprise a docking station and/or an interfaceconfigured to interact with a docking station for personal mobile mediaplayback devices. In certain embodiments, a playback device may beintegral to another device or component such as a television, a lightingfixture, or some other device for indoor or outdoor use. In someembodiments, a playback device omits a user interface and/or one or moretransducers. For example, FIG. 1D is a block diagram of a playbackdevice 110 p comprising the input/output 111 and electronics 112 withoutthe user interface 113 or transducers 114.

FIG. 1E is a block diagram of a bonded playback device 110 q comprisingthe playback device 110 a (FIG. 1C) sonically bonded with the playbackdevice 110 i (e.g., a subwoofer) (FIG. 1A). In the illustratedembodiment, the playback devices 110 a and 110 i are separate ones ofthe playback devices 110 housed in separate enclosures. In someembodiments, however, the bonded playback device 110 q includes a singleenclosure housing both the playback devices 110 a and 110 i. The bondedplayback device 110 q can be configured to process and reproduce sounddifferently than an unbonded playback device (e.g., the playback device110 a of FIG. 1C) and/or paired or bonded playback devices (e.g., theplayback devices 110 l and 110 m of FIG. 1B). In some embodiments, forexample, the playback device 110 a is full-range playback deviceconfigured to render low frequency, mid-range frequency, and highfrequency audio content, and the playback device 110 i is a subwooferconfigured to render low frequency audio content. In some aspects, theplayback device 110 a, when bonded with the first playback device, isconfigured to render only the mid-range and high frequency components ofa particular audio content, while the playback device 110 i renders thelow frequency component of the particular audio content. In someembodiments, the bonded playback device 110 q includes additionalplayback devices and/or another bonded playback device.

c. Suitable Network Microphone Devices (NMDs)

FIG. 1F is a block diagram of the NMD 120 a (FIGS. 1A and 1B). The NMD120 a includes one or more voice processing components 124 (hereinafter“the voice components 124”) and several components described withrespect to the playback device 110 a (FIG. 1C) including the processors112 a, the memory 112 b, and the microphones 115. The NMD 120 aoptionally includes other components also included in the playbackdevice 110 a (FIG. 1C), such as the user interface 113 and/or thetransducers 114. In some embodiments, the NMD 120 a is configured as amedia playback device (e.g., one or more of the playback devices 110),and further includes, for example, one or more of the audio components112 g (FIG. 1C), the amplifiers 114, and/or other playback devicecomponents. In certain embodiments, the NMD 120 a includes an Internetof Things (IoT) device such as, for example, a thermostat, alarm panel,fire and/or smoke detector, etc. In some embodiments, the NMD 120 aincludes the microphones 115, the voice processing 124, and only aportion of the components of the electronics 112 described above withrespect to FIG. 1B. In some aspects, for example, the NMD 120 a includesthe processor 112 a and the memory 112 b (FIG. 1B), while omitting oneor more other components of the electronics 112. In some embodiments,the NMD 120 a includes additional components (e.g., one or more sensors,cameras, thermometers, barometers, hygrometers).

In some embodiments, an NMD can be integrated into a playback device.FIG. 1G is a block diagram of a playback device 110 r comprising an NMD120 d. The playback device 110 r can comprise many or all of thecomponents of the playback device 110 a and further include themicrophones 115 and voice processing 124 (FIG. 1F). The playback device110 r optionally includes an integrated control device 130 c. Thecontrol device 130 c can comprise, for example, a user interface (e.g.,the user interface 113 of FIG. 1B) configured to receive user input(e.g., touch input, voice input) without a separate control device. Inother embodiments, however, the playback device 110 r receives commandsfrom another control device (e.g., the control device 130 a of FIG. 1B).

Referring again to FIG. 1F, the microphones 115 are configured toacquire, capture, and/or receive sound from an environment (e.g., theenvironment 101 of FIG. 1A) and/or a room in which the NMD 120 a ispositioned. The received sound can include, for example, vocalutterances, audio played back by the NMD 120 a and/or another playbackdevice, background voices, ambient sounds, etc. The microphones 115convert the received sound into electrical signals to produce microphonedata. The voice processing 124 receives and analyzes the microphone datato determine whether a voice input is present in the microphone data.The voice input can comprise, for example, an activation word followedby an utterance including a user request. As those of ordinary skill inthe art will appreciate, an activation word is a word or other audio cuethat signifying a user voice input. For instance, in querying theAMAZON® VAS, a user might speak the activation word “Alexa.” Otherexamples include “Ok, Google” for invoking the GOOGLE® VAS and “Hey,Siri” for invoking the APPLE® VAS.

After detecting the activation word, voice processing 124 monitors themicrophone data for an accompanying user request in the voice input. Theuser request may include, for example, a command to control athird-party device, such as a thermostat (e.g., NEST® thermostat), anillumination device (e.g., a PHILIPS HUE® lighting device), or a mediaplayback device (e.g., a Sonos® playback device). For example, a usermight speak the activation word “Alexa” followed by the utterance “setthe thermostat to 68 degrees” to set a temperature in a home (e.g., theenvironment 101 of FIG. 1A). The user might speak the same activationword followed by the utterance “turn on the living room” to turn onillumination devices in a living room area of the home. The user maysimilarly speak an activation word followed by a request to play aparticular song, an album, or a playlist of music on a playback devicein the home.

d. Suitable Control Devices

FIG. 1H is a partially schematic diagram of the control device 130 a(FIGS. 1A and 1B). As used herein, the term “control device” can be usedinterchangeably with “controller” or “control system.” Among otherfeatures, the control device 130 a is configured to receive user inputrelated to the media playback system 100 and, in response, cause one ormore devices in the media playback system 100 to perform an action(s) oroperation(s) corresponding to the user input. In the illustratedembodiment, the control device 130 a includes a smartphone (e.g., aniPhone™, an Android phone) on which media playback system controllerapplication software is installed. In some embodiments, the controldevice 130 a includes, for example, a tablet (e.g., an iPad™), acomputer (e.g., a laptop computer, a desktop computer), and/or anothersuitable device (e.g., a television, an automobile audio head unit, anIoT device). In certain embodiments, the control device 130 a includes adedicated controller for the media playback system 100. In otherembodiments, as described above with respect to FIG. 1G, the controldevice 130 a is integrated into another device in the media playbacksystem 100 (e.g., one more of the playback devices 110, NMDs 120, and/orother suitable devices configured to communicate over a network).

The control device 130 a includes electronics 132, a user interface 133,one or more speakers 134, and one or more microphones 135. Theelectronics 132 comprise one or more processors 132 a (referred tohereinafter as “the processors 132 a”), a memory 132 b, softwarecomponents 132 c, and a network interface 132 d. The processor 132 a canbe configured to perform functions relevant to facilitating user access,control, and configuration of the media playback system 100. The memory132 b can comprise data storage that can be loaded with one or more ofthe software components executable by the processor 302 to perform thosefunctions. The software components 132 c can comprise applicationsand/or other executable software configured to facilitate control of themedia playback system 100. The memory 112 b can be configured to store,for example, the software components 132 c, media playback systemcontroller application software, and/or other data associated with themedia playback system 100 and the user.

The network interface 132 d is configured to facilitate networkcommunications between the control device 130 a and one or more otherdevices in the media playback system 100, and/or one or more remotedevices. In some embodiments, the network interface 132 is configured tooperate according to one or more suitable communication industrystandards (e.g., infrared, radio, wired standards including IEEE 802.3,wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, 802.15, 4G, LTE). The network interface 132 d can beconfigured, for example, to transmit data to and/or receive data fromthe playback devices 110, the NMDs 120, other ones of the controldevices 130, one of the computing devices 106 of FIG. 1B, devicescomprising one or more other media playback systems, etc. Thetransmitted and/or received data can include, for example, playbackdevice control commands, state variables, playback zone and/or zonegroup configurations. For instance, based on user input received at theuser interface 133, the network interface 132 d can transmit a playbackdevice control command (e.g., volume control, audio playback control,audio content selection) from the control device 304 to one or more ofthe playback devices 100. The network interface 132 d can also transmitand/or receive configuration changes such as, for example,adding/removing one or more playback devices 100 to/from a zone,adding/removing one or more zones to/from a zone group, forming a bondedor consolidated player, separating one or more playback devices from abonded or consolidated player, among others. Additional description ofzones and groups can be found below with respect to FIGS. 1-I through1M.

The user interface 133 is configured to receive user input and canfacilitate ‘control of the media playback system 100. The user interface133 includes media content art 133 a (e.g., album art, lyrics, videos),a playback status indicator 133 b (e.g., an elapsed and/or remainingtime indicator), media content information region 133 c, a playbackcontrol region 133 d, and a zone indicator 133 e. The media contentinformation region 133 c can include a display of relevant information(e.g., title, artist, album, genre, release year) about media contentcurrently playing and/or media content in a queue or playlist. Theplayback control region 133 d can include selectable (e.g., via touchinput and/or via a cursor or another suitable selector) icons to causeone or more playback devices in a selected playback zone or zone groupto perform playback actions such as, for example, play or pause, fastforward, rewind, skip to next, skip to previous, enter/exit shufflemode, enter/exit repeat mode, enter/exit cross fade mode, etc. Theplayback control region 133 d may also include selectable icons tomodify equalization settings, playback volume, and/or other suitableplayback actions. In the illustrated embodiment, the user interface 133includes a display presented on a touch screen interface of a smartphone(e.g., an iPhone™, an Android phone). In some embodiments, however, userinterfaces of varying formats, styles, and interactive sequences mayalternatively be implemented on one or more network devices to providecomparable control access to a media playback system.

The one or more speakers 134 (e.g., one or more transducers) can beconfigured to output sound to the user of the control device 130 a. Insome embodiments, the one or more speakers comprise individualtransducers configured to correspondingly output low frequencies,mid-range frequencies, and/or high frequencies. In some aspects, forexample, the control device 130 a is configured as a playback device(e.g., one of the playback devices 110). Similarly, in some embodimentsthe control device 130 a is configured as an NMD (e.g., one of the NMDs120), receiving voice commands and other sounds via the one or moremicrophones 135.

The one or more microphones 135 can comprise, for example, one or morecondenser microphones, electret condenser microphones, dynamicmicrophones, and/or other suitable types of microphones or transducers.In some embodiments, two or more of the microphones 135 are arranged tocapture location information of an audio source (e.g., voice, audiblesound) and/or configured to facilitate filtering of background noise.Moreover, in certain embodiments, the control device 130 a is configuredto operate as playback device and an NMD. In other embodiments, however,the control device 130 a omits the one or more speakers 134 and/or theone or more microphones 135. For instance, the control device 130 a maycomprise a device (e.g., a thermostat, an IoT device, a network device)comprising a portion of the electronics 132 and the user interface 133(e.g., a touch screen) without any speakers or microphones. Additionalcontrol device embodiments are described in further detail below withrespect to FIGS. 4A-4D and 5.

III. Example Wireless Earbud Charging System

As noted above, example implementations may involve a pair of earbuds.To illustrate, FIG. 2A is a block diagram of an example earbud 210 a.The earbud 210 a may be used in a pair with another earbud 210 (e.g., anearbud 210 b). As shown in the block diagram of FIG. 2A, the earbud 210a includes several of the same or similar components as the playbackdevice 110 a. However, to facilitate portable use, the earbud 210 a isimplemented in an earbud form factor and includes an internal battery inpower 212 i to provide portable power.

The earbud 210 a includes an input/output 211, which can include ananalog I/O 211 a and/or a digital I/O 211 b similar to the components ofthe playback device 110. The earbud 210 a further include electronics212, a user interface 213 (e.g., one or more buttons, knobs, dials,touch-sensitive surfaces, displays, touchscreens), and one or moretransducers 214 (referred to hereinafter as “the transducers 214”). Theelectronics 212 is configured to receive audio from an audio source viathe input/output 211 and/or one or more of the computing devices 106 a-cvia the network 104 (FIG. 1B)), amplify the received audio, and outputthe amplified audio for playback via one or more of the transducers 214.

In some embodiments, the earbud 210 a optionally includes one or moremicrophones 215 (e.g., a single microphone, a plurality of microphones,a microphone array) (hereinafter referred to as “the microphones 215”).In certain embodiments, for example, the earbud 210 a having one or moreof the optional microphones 215 can operate as an NMD configured toreceive voice input from a user and correspondingly perform one or moreoperations based on the received voice input.

In the illustrated embodiment of FIG. 2A, the electronics 212 includeone or more processors 212 a (referred to hereinafter as “the processors212 a”), memory 212 b, software components 212 c, a network interface212 d, one or more audio processing components 212 g (referred tohereinafter as “the audio components 212 g”), one or more audioamplifiers 212 h (referred to hereinafter as “the amplifiers 212 h”),and power 212 i (e.g., one or more power supplies, power cables, powerreceptacles, batteries, induction coils, Power-over Ethernet (POE)interfaces, and/or other suitable sources of electric power). In someembodiments, the electronics 212 optionally include one or more othercomponents 212 j (e.g., one or more sensors, video displays,touchscreens).

The network interface 212 d is configured to facilitate a transmissionof data between the earbud 210 a and one or more other devices on a datanetwork such as, for example, the links 103 and/or the network 104 (FIG.1B). The network interface 212 d is configured to transmit and receivedata corresponding to media content (e.g., audio content, video content,text, photographs) and other signals (e.g., non-transitory signals)comprising digital packet data including an Internet Protocol (IP)-basedsource address and/or an IP-based destination address. The networkinterface 212 d can parse the digital packet data such that theelectronics 212 properly receives and processes the data destined forthe earbud 210 a.

In the illustrated embodiment of FIG. 2A, the network interface 212 dincludes an 802.15 interface 212 e (referred to hereinafter as “the802.15 interface 212 e”) and a 802.11 interface 212 f. The networkinterface 212 d (e.g., suitable interfaces comprising one or moreantennae) can be configured to wirelessly communicate with one or moreother devices (e.g., one or more of the playback devices 110, NMDs 120,control devices 130 that are communicatively coupled to the network 104(FIG. 1B) in accordance with a suitable wireless communication protocol(e.g., WiFi, LTE). Further, the network interface 212 d can beconfigured to wirelessly communicate with an earbud 210 b to form a pairof earbuds 210.

In some embodiments, the network interface 212 d optionally includes awired interface (e.g., an interface or receptacle configured to receivea network cable such as an Ethernet, a USB-A, USB-C, and/or Thunderboltcable) configured to communicate over a wired connection with otherdevices in accordance with a suitable wired communication protocol. Insome embodiments, the electronics 212 excludes the network interface 212d altogether and transmits and receives media content and/or other datavia another communication path (e.g., the input/output 711).

The audio components 212 g are configured to process and/or filter datacomprising media content received by the electronics 212 (e.g., via theinput/output 211 and/or the network interface 212 d) to produce outputaudio signals. In some embodiments, the audio processing components 212g comprise, for example, one or more digital-to-analog converters (DAC),audio preprocessing components, audio enhancement components, a digitalsignal processors (DSPs), and/or other suitable audio processingcomponents, modules, circuits, etc. In certain embodiments, one or moreof the audio processing components 212 g can comprise one or moresubcomponents of the processors 212 a. In some embodiments, theelectronics 212 omits the audio processing components 212 g. In someaspects, for example, the processors 212 a execute instructions storedon the memory 212 b to perform audio processing operations to producethe output audio signals.

The amplifiers 212 h are configured to receive and amplify the audiooutput signals produced by the audio processing components 212 g and/orthe processors 212 a. The amplifiers 212 h can comprise electronicdevices and/or components configured to amplify audio signals to levelssufficient for driving one or more of the transducers 214. In someembodiments, for example, the amplifiers 212 h include one or moreswitching or class-D power amplifiers. In other embodiments, however,the amplifiers include one or more other types of power amplifiers(e.g., linear gain power amplifiers, class-A amplifiers, class-Bamplifiers, class-AB amplifiers, class-C amplifiers, class-D amplifiers,class-E amplifiers, class-F amplifiers, class-G and/or class Hamplifiers, and/or another suitable type of power amplifier). In certainembodiments, the amplifiers 212 h comprise a suitable combination of twoor more of the foregoing types of power amplifiers. Moreover, in someembodiments, individual ones of the amplifiers 212 h correspond toindividual ones of the transducers 214. In other embodiments, however,the electronics 212 includes a single one of the amplifiers 212 hconfigured to output amplified audio signals to a plurality of thetransducers 214.

The transducers 214 (e.g., one or more speakers and/or speaker drivers)receive the amplified audio signals from the amplifier 212 h and renderor output the amplified audio signals as sound (e.g., audible soundwaves having a frequency between about 20 Hertz (Hz) and 20 kilohertz(kHz)). In some embodiments, the transducers 214 can comprise a singletransducer. In other embodiments, however, the transducers 214 comprisea plurality of audio transducers. In some embodiments, the transducers214 comprise more than one type of transducer. For example, thetransducers 214 can include one or more low frequency transducers (e.g.,subwoofers, woofers), mid-range frequency transducers (e.g., mid-rangetransducers, mid-woofers), and one or more high frequency transducers(e.g., one or more tweeters).

Within example implementations, the earbud 210 a may operate in one of afirst mode and a second mode. In the first mode, the earbud 210 aoperates independently of the media playback system 100. While in thesecond mode, the earbud 210 a operates as part of the media playbacksystem 100. Generally, the earbud 210 a operates in the first mode whilein the physical proximity of the media playback system 100 (e.g., whilein the home) to facilitate interoperability with the playback device 110a-n of the media playback system 100 and operates in the second modewhile “on the go,” but the earbud 210 a may also be operable in thesecond mode while in the physical proximity of the media playback system100. The portable playback device 710 may switch between modes manually(e.g., via user input to a user interface 213) or automatically (e.g.,based on proximity to one or more playback devices 110 a-n).

In the first mode, the earbud 210 a may interface with other devices ofthe media playback system 100. For instance, the earbud 210 a may formsynchrony groupings or other arrangements with the playback devices 110a-n in the first mode. Further, in the first mode, the earbud 210 a maybe controlled by the control device(s) 130 in the same or similar manneras the playback device(s) 110.

In the second mode, rather than operating as one playback device of themedia playback system 100, the earbud 210 a operates independently. Asnoted above, this mode can be utilized “on the go” to facilitateplayback away from the media playback system 100. Further, this mode canbe used in proximity to the media playback system 100, which mayfacilitate more private use of the earbud 210 a.

FIG. 2B is a partial cutaway side view of the earbud 210 a configured inaccordance with aspects of the disclosed technology. As shown in FIG.2B, the earbud 210 a includes a housing 216. Various components of theearbud 210 a may be carried in the housing 216, such as the input/output211, the electronics 212, the user interface 213, and/or the transducers214.

A first portion of the housing 216 (labeled 216 a) is insertable into anear canal. The first portion 216 a carries a first transducer 214 ainternally. The first transducer 214 a is arranged in the first portion216 a to direct sound produced by the first transducer 214 a into theear canal when the first portion 216 a is inserted in the ear canal.

A second portion of the housing (labeled 216 b) carries acharging-adapter connection interface 217 (referred to herein as aconnection interface 217). The connection interface 217 includes magnets218 (labelled individually as a first magnet 218 a and a second magnet218 b). The magnets 218 attach a charging adapter 340 a (FIG. 3A)externally to the housing 216 of the earbud 210 a (i.e., to the firstportion 216 a). Further, the magnets 218 align electrodes 219 of theearbud 210 a with electrodes of the charging adapter 340 a (FIG. 3A). Inalternate implementations, the connection interface may utilizemechanical connectors in addition to or as an alternative to the magnets218.

FIG. 3A shows an example charging adapter 340 a configured in accordancewith aspects of the disclosed technology. The charging adapter 340 aincludes a housing 316, which carries a power 312 i that includes one ormore adapter batteries. As shown, the housing 316 is substantiallycoin-shaped, which may facilitate attaching the charging adapter 340 ato the earbud 210 a and/or inserting the charging adapter 340 a into acharging case 450 (FIGS. 4 and 6).

The charging adapter 340 a further includes magnets 318 (labelledindividually as a first magnet 318 a, a second magnet 318 b, a thirdmagnet 318 c, and a fourth magnet 318 d). The magnets 318 a and 318 bfacilitate attachment of the charging adapter 340 a to the connectioninterface 217 of the earbud 210 a.

To illustrate, FIGS. 3B and 3C illustrate exemplary attachment of thecharging adapter 340 a to the earbud 210 a. In particular, asillustrated in FIG. 3B, the magnets 218 a and 218 b of the earbud 210 aare attracted to the magnets 318 a and 318 b, respectively, of thecharging adapter 340 a. This magnetic attraction causes the chargingadapter 340 a to attach to the connection interface 217 of the earbud210 a when in proximity to the connection interface 217.

FIG. 3C shows the charging adapter 340 a attached to the earbud 210 a.When attached, the electrodes 219 of the earbud 210 a are aligned withthe electrodes 319 a of the charging adapter 340 a allowing current tobe drawn from the adapter batteries of the charging adapter 340 a. Theearbud 210 a uses this current to charge the battery or batteries of thepower 212 i.

In an example, a controller of the earbud 210 a (which may beimplemented via the processors 212 a, the memory 212 b, and the softwarecomponents 212 b) detects attachment of the first charging adapter tothe magnetic interface, such as via completion of a circuit includingthe electrodes 219. Based on detecting that the first charging adapteris attached to the magnetic interface, the controller causes the batteryor batteries of the power 212 i to charge from the charging adapter 340a. Charging the battery or batteries of the power 212 i may involvedrawing current from the one or more adapter batteries of the chargingadapter 340 a via the electrodes 219 of the connection interface 217 andthe electrodes 319 a of the charging adapter 340.

FIG. 4 shows an example charging case 450. The charging case 450 aincludes a housing 416, which carries a power 412 i. The housing 416forms a first volume 452 a shaped to carry the charging adapter 340 aand the earbud 210 a when the charging adapter 340 a and the earbud 210a are attached. The housing 416 also forms a second volume 452 b shapedto carry a second charging adapter 340 b and a second earbud 210 b whenthe charging adapter 340 b and the earbud 210 b are attached.

The power 412 i may include that includes one or more case batteriesconfigured to charge the earbuds 210 a and 210 b and/or the chargingadapters 340 a and 340 b. Further, the power 412 i may include one ormore coils. A wireless charger may induce a current in the one or morecoils to wirelessly charge the one or more case batteries from wallpower connected to the wireless charger. Additionally or alternatively,the power 412 may include a cable port. A cable connected between thecable port and a wall charger may deliver current to charge the one ormore case batteries from wall power connected to the wall charger.

In the housing 416, electrodes 419 a are arranged to contact theelectrodes 319 b of the charging adapter 340 a when the charging adapter340 a is carried in the first volume 452 a formed by the housing 416. Tomaintain the charging adapter 340 a in the first volume 452 a, thecharging case 450 a includes magnets 418 a and 418 b. Further, tomaintain the earbud 210 a in the first volume 452 a, the charging case450 a optionally includes one or more magnets 418 e. The magnets 218 ofthe earbud 210 a and the magnets 318 a and 318 b of the charging adapter340 a may also or alternatively maintain the earbud 210 a in the firstvolume 452 a.

Similarly, in the housing 416, electrodes 419 b are arranged to contactthe electrodes 319 b of a second charging adapter 340 b when thecharging adapter 340 b is carried in the second volume 452 b formed bythe housing 416. To maintain the charging adapter 340 b in the secondvolume 452 b, the charging case 450 a includes magnets 418 c and 418 d.Further, to maintain the earbud 210 b in the second volume 452 a, thecharging case 450 a optionally includes one or more magnets 418 fHowever, similar to the earbud 210 a, the magnets 218 of the earbud 210b and the magnets 318 a and 318 b of the charging adapter 340 b may alsoor alternatively maintain the earbud 210 b in the second volume 452 b.

To illustrate, FIG. 5A, 5B, and 5C illustrate example carrying of theearbuds 310 a and 210 b as well as the charging adapters 340 a and 340 bin the charging case 450 a. FIG. 5A illustrates how the magnets 418 aand 418 b align with the magnets 318 c and 318 d of the charging adapter340 a. Further, as described above, the magnets 318 a and 318 b alignwith the magnets 218 a and 218 b of the earbud 210 a. Yet further, oneor more magnets 218 c align with the one or more magnets 418 e.

When the earbud 210 a, the charging adapter 340 a, and the charging case450 a are brought into proximity while keeping the magnets 218, 318, and418 aligned, the magnets 218, 318, and 418 maintain the charging adapter340 a and earbud 210 a within the first volume 452 b. Correspondingmagnets maintain the charging adapter 340 b and earbud 210 b within thesecond volume 452 b.

To illustrate, FIG. 5B shows the charging adapters 340 a and 340 bcarried in the first volume 452 a and the second volume 452 b. Thecharging adapters 340 a and 340 b are maintained in the first volume 452a and the second volume 452 b via the magnets 318 and 418, as shown.

FIG. 5C shows the charging adapter 340 a and the earbud 210 a carried inthe first volume 452 a and the charging adapter 340 b and the earbud 210b carried in the second volume 452 b. The earbuds 210 a and 210 b andcharging adapters 340 a and 340 b are maintained in the first volume 452a and the second volume 452 b via the magnets 218, 318 and 418, asshown. A cover 416 a may optionally be placed on or connected to thehousing 416.

FIG. 5D illustrates how the earbud 210 a and charging adapter 340 a maybe inserted into the charging case 450 a while attached to one another.Similar, the earbud 210 b and charging adapter 340 b may be insertedinto the charging case 450 a while attached to one another. In someembodiments, the charging adapters 340 a and 340 b are interchangeablebetween the earbuds 310 a and 310 b. Further, in such examples, thecharging adapters 340 a and 340 b may be carried in either the firstvolume 452 a or the second volume 452 b.

Carrying the earbuds 210 a and 210 b and charging adapters 340 a and 340b as shown in FIGS. 5A, 5B, 5C, and 5D facilities charging of theearbuds 210 a and 210 b and/or the charging adapters 340 a and 340 b. Inparticular, when the charging adapter 340 a is carried in the chargingcase 450 a as shown in FIGS. 5B and 5C, the electrodes 319 b of thecharging adapter 340 a align and contact the electrodes 419 a of thecharging case 450 a. This allows the charging adapter 340 a to drawcurrent from the case batteries of the charging case 450 a or wall power(e.g., if the charging case is connected to wall power). The chargingadapter 340 b may charge similarly using the electrodes 419 b.

Similarly, when the earbud 210 a is carried in the charging case 450 aas shown in FIG. 5C, the electrodes 319 a of the charging adapter 340 aalign and contact the electrodes 218 b of the charging case 450 a. Thisallows the earbud 210 a to draw current from the charging adapter 340 a.In some embodiments, the earbud 210 a charges from the adapter batteriesof the charging adapter 340 a (which may be concurrently or laterrecharged using the case batteries of the charging case 450 a or wallpower). Alternatively, the charging adapter 340 a may direct currentfrom the electrodes 419 a through the electrodes 319 b and 318 a to theelectrodes 218 a of the earbud 210 a. The earbud 210 b may chargesimilarly when carried in the volume 252 b.

FIG. 6A shows another example charging case 650. Like the charging case450, the charging case 650 includes a housing 616 carrying a power 612that includes one or more case batteries. Further, the housing 616 formsa first volume 652 a configured to carry the earbud 210 a and thecharging adapter 340 a, as well as the corresponding electrodes 619 aand magnets 618 a, 618 b, and 618 e. Yet further, the housing 616 formsa second volume 652 b configured to carry the earbud 210 b and thecharging adapter 340 b, as well as the corresponding electrodes 619 band magnets 618 c, 618 d, and 618 f.

In contrast to the charging case 450, the housing of the charging case650 forms a third volume 652 c and a fourth volume 652 d. The thirdvolume 652 c is formed to carry a third charging adapter 340 c while thefourth volume 652 d is formed to carry a fourth charging adapter 340 d.Magnets 618 g and 618 h maintain the third charging adapter 340 c in thethird volume 652. While the third charging adapter 340 c is carried inthe third volume 652 c, the electrodes 619 c align with and connect withelectrodes of the third charging adapter 340 c, allowing the thirdcharging adapter 340 c to charge from the case batteries or wall power.Similarly, magnets 618 i and 618 k maintain the fourth charging adapter340 d in the fourth volume 652 d. While the fourth charging adapter 340d is carried in the third volume 652 d, the electrodes 619 d align withand connect with electrodes of the fourth charging adapter 340 d,allowing the fourth charging adapter 340 d to charge from the casebatteries or wall power. If the charging adapters 340 a and 340 b becomedrained, a user can swap out the charging adapters 340 c and 340 d tocontinue charging the earbuds 210 without necessarily interruptingplayback.

FIG. 6B shows a partial cutaway side view of a pair of earbuds 710(labelled as earbud 710 a and 710 b), a first charging adapter 740 a, asecond charging adapter 740 b, and a charging case 750. The earbuds 710,the charging adapters 740 a and 740 b, and the charging case 750generally function similarly as the earbuds 210, charging adapters 340,and charging cases 450 and 650.

As shown in FIG. 6B, a housing 716 carries a power 712 that includes oneor more case batteries. Further, the housing 716 of the charging case750 forms a first volume 752 a and a second volume 752 b. The firstvolume 752 a is configured to carry the earbud 710 a while the secondvolume 752 b is formed to carry the earbud 710 b. Magnets in the housing716 and/or a connection interface 717 a of the earbud 710 a maintain theearbud 710 a in the first volume 752 a. Similarly, magnets in thehousing 716 and/or a connection interface 717 b of the earbud 710 bmaintain the earbud 710 b in the second volume 752 b. Further, themagnets and the shape of the first volume 752 a align electrodes of theconnection interface 717 a with corresponding electrodes in the housing716, allowing the earbud 710 a to charge from the case batteries of thepower 712. The earbud 710 b can likewise charge when carried in thesecond volume 752 b, as shown.

Yet further, as also shown in FIG. 6B, the charging adapter 740 a isattachable to the earbud 710 a via a connection interface 717 c.Similarly, the charging adapter 740 b is attachable to the earbud 710 bvia a connection interface 717 d. Each of the charging adapters 740 aand 740 b can charge the corresponding earbuds 710 a and 710 b whenattached to the earbuds 710 a and 710 b (and not carried in the chargingcase 750). Further, each of the charging adapters 740 a and 740 b can becharged by the one or more case batteries (or wall power deliveredthrough the charging case 750) via the earbud 710 a or the earbud 710 b(i.e., through the electrodes of the connection interfaces 717 a and 717c or the connection interfaces 717 b and 717 d) when attached to theearbuds 710 a and 710 b (and the earbuds 710 are carried in the chargingcase 750).

In further embodiments, example earbuds utilize charging adapters asinternal battery packs. In such examples, the charging adapters may beremovable and swapped with (charged) charging adapters from the chargingcase. Other examples are possible as well.

Yet further, in some examples, example charging adapters may be attachedto other portable playback devices, such as headphones. For instance,example headphones may include similar connection interfaces as theearbuds. By attaching a charging adapter to the headphones, internalbatteries of the headphones may be charged from the adapter batteries ofthe charging adapter.

In further examples, the charging adapter may include an around the earclip to support the additional mass of the charging adapter. In suchexamples, attaching the charging adapter to an earbud may arrange theear clip to be supported by the ear lobe when the ear bud is inserted inthe ear canal. Other examples are possible as well.

IV. Example Charging Techniques

FIG. 7 is a flow diagram showing an example method 700 facilitatecharging of one or more wireless earbuds. The method 700 may beperformed by an earbud, such as the earbud 210 a (FIG. 2A).Alternatively, the method 700 may be performed by any suitable device orby a system of devices, such as a system comprising the pair of earbuds710, among other examples.

At block 702, the method 700 includes detecting attachment of a firstcharging adapter to a magnetic interface. For instance, the earbud 210 amay detect attachment of the charging adapter 340 a using the magnets218 and 318 (FIG. 3B) using the electronics 210 (FIG. 2A). As anotherexample, the earbud 740 a may detect attachment of the charging adapter740 a (FIG. 6B). In some examples, a second earbud (e.g., the earbud 210b) may detect attachment of a second charging adapter 340 b.

At block 704, the method 700 includes causing a first internal batteryto charge from the first charging adapter. For example, the earbud 210 amay cause the internal battery in power 212 i (FIG. 2A) to charge fromthe charging adapter 340 a (FIG. 3D). Charging the first internalbattery may involve drawing current from the one or more adapterbatteries of the first charging adapter via the electrodes (e.g., theelectrodes 219) of the magnetic connection interface and the electrodesof the first charging adapter (e.g., the electrodes 319) (FIG. 3D). Insome examples, a second earbud (e.g., the earbud 210 b) may cause asecond internal battery to charge from a second charging adapter (e.g.,the charging adapter 340 b), When the first charging adapter 340 a isdetached from the magnetic interface, the earbud 210 a stops charging.

At block 706, the method 700 includes playing back audio content. Forinstance, the earbud 210 a, possibly in a stereo pair with anotherearbud (e.g., the earbud 210 b), may play back audio content. Playingback audio content may involve streaming data representing audio from aremote source using the network interface 212 d, processing the audiousing the processors 212 a and/or the audio processing components 212 g,and outputting the audio using the transducers 214 (FIG. 2A). Duringplayback, the components of the earbud 210 a may be powered by theinternal battery of the power 212 i, which may be charging from thecharging adapter.

In some cases, the method 700 further involves detecting that a batterylevel of the internal battery is below a threshold level. Based on suchdetecting, the earbud 210 a may output an indication that the batterylevel is low. For instance, the earbud 210 a may play back an audiblenotification that the battery level is low and that the user shouldattach a charging adapter to continue use of the earbud 210 a.

V. Additional Examples

FIG. 8A is a front isometric view of earbuds 810 including an earbud 810a and an earbud 810 b configured in accordance with aspects of thedisclosed technology. As shown, the earbuds 800 are carried in acharging case 850.

FIG. 8B is a bottom view of the charging case 850.

FIG. 8C is a top view of the charging case 850.

FIG. 8D is a first side view of the charging case 850.

FIG. 8E is a second side view of the charging case 850.

FIG. 8F is a front isometric view of the earbud 810 a and the earbud 810b illustrating exemplary arrangement with the charging case 850. Acharging adapter 840 a is attached to an exterior surface of the earbud810 a, as shown. Similarly, a charging adapter 840 b is attached to anexterior surface of the earbud 810 b, as also shown.

FIG. 8G is an isometric view of the earbud 810 a and the chargingadapter 840 a.

FIG. 8H is a first side view of the earbud 810 a and the chargingadapter 840 a.

FIG. 8I is a second side view of the earbud 810 a and the chargingadapter 840 a.

FIG. 8J is a third side view of the earbud 810 a and the chargingadapter 840 a.

FIG. 8K is a fourth side view of the earbud 810 a and the chargingadapter 840 a.

FIG. 8L is a fifth side view of the earbud 810 a.

FIG. 8M is a sixth side view of the earbud 810 a.

FIG. 9A is a front view of headphones 910 configured in accordance withaspects of the disclosed technology.

FIG. 9B is a first side view of the headphones 910. A charging adapter940 a is attached to a first exterior surface of the headphones 910, asshown.

FIG. 9B is a second side view of the headphones 910. A charging adapter940 b is attached to a second exterior surface of the headphones 910, asalso shown.

VI. Conclusion

The above discussions relating to playback devices, controller devices,playback zone configurations, and media content sources provide onlysome examples of operating environments within which functions andmethods described below may be implemented. Other operating environmentsand configurations of media playback systems, playback devices, andnetwork devices not explicitly described herein may also be applicableand suitable for implementation of the functions and methods.

The description above discloses, among other things, various examplesystems, methods, apparatus, and articles of manufacture including,among other components, firmware and/or software executed on hardware.It is understood that such examples are merely illustrative and shouldnot be considered as limiting. For example, it is contemplated that anyor all of the firmware, hardware, and/or software aspects or componentscan be embodied exclusively in hardware, exclusively in software,exclusively in firmware, or in any combination of hardware, software,and/or firmware. Accordingly, the examples provided are not the onlyways) to implement such systems, methods, apparatus, and/or articles ofmanufacture.

Additionally, references herein to “embodiment” means that a particularfeature, structure, or characteristic described in connection with theembodiment can be included in at least one example embodiment of aninvention. The appearances of this phrase in various places in thespecification are not necessarily all referring to the same embodiment,nor are separate or alternative embodiments mutually exclusive of otherembodiments. As such, the embodiments described herein, explicitly andimplicitly understood by one skilled in the art, can be combined withother embodiments.

The specification is presented largely in terms of illustrativeenvironments, systems, procedures, steps, logic blocks, processing, andother symbolic representations that directly or indirectly resemble theoperations of data processing devices coupled to networks. These processdescriptions and representations are typically used by those skilled inthe art to most effectively convey the substance of their work to othersskilled in the art. Numerous specific details are set forth to provide athorough understanding of the present disclosure. However, it isunderstood to those skilled in the art that certain embodiments of thepresent disclosure can be practiced without certain, specific details.In other instances, well known methods, procedures, components, andcircuitry have not been described in detail to avoid unnecessarilyobscuring aspects of the embodiments. Accordingly, the scope of thepresent disclosure is defined by the appended claims rather than theforegoing description of embodiments.

When any of the appended claims are read to cover a purely softwareand/or firmware implementation, at least one of the elements in at leastone example is hereby expressly defined to include a tangible,non-transitory medium such as a memory, DVD, CD, Blu-ray, and so on,storing the software and/or firmware.

The present technology is illustrated, for example, according to variousaspects described below. Various examples of aspects of the presenttechnology are described as numbered examples (1, 2, 3, etc.) forconvenience. These are provided as examples and do not limit the presenttechnology. It is noted that any of the dependent examples may becombined in any combination, and placed into a respective independentexample. The other examples can be presented in a similar manner.

EXAMPLE 1

A system comprising: a first charging adapter comprising one or moreadapter batteries; and a first earbud, the first earbud comprising: afirst IEEE 802.15-compatible interface; a first internal battery; afirst audio driver; a housing carrying the first IEEE 802.15-compatibleinterface and the first internal battery, wherein the housing of thefirst earbud comprises: a first portion insertable into a first earcanal, the first portion carrying the first audio driver; and a secondportion carrying a magnetic interface that includes one or more magnetsthat (i) attach the first charging adapter externally to the housing ofthe first earbud and (ii) align electrodes of the first charging adapterto electrodes of the magnetic interface; and a first controller carriedin the housing of the first earbud and configured to perform functionscomprising: detecting attachment of the first charging adapter to themagnetic interface; and based on detecting that the first chargingadapter is attached to the magnetic interface, causing the firstinternal battery to charge from the first charging adapter, whereincharging the first internal battery comprises drawing current from theone or more adapter batteries of the first charging adapter via theelectrodes of the magnetic connection interface and the electrodes ofthe first charging adapter.

EXAMPLE 2

The system of example 1, further comprising: a second charging adaptercomprising one or more adapter batteries; and a second earbud, thesecond earbud comprising: a second IEEE 802.15-compatible interface; asecond internal battery; a second audio driver; a housing carrying thesecond IEEE 802.15-compatible interface and the second internal battery,wherein the housing of the second earbud comprises: a first portioninsertable into a second ear canal, the first portion carrying thesecond audio driver; and a second portion carrying a magnetic interfacethat includes one or more magnets that (i) attach the second chargingadapter externally to the housing of the second earbud and (ii) alignelectrodes of the second charging adapter to electrodes of the magneticinterface; a second controller carried in the housing of the secondearbud and configured to perform functions comprising: detectingattachment of the second charging adapter to the magnetic interface; andbased on detecting that the second charging adapter is attached to themagnetic interface, causing the second internal battery to charge fromthe second charging adapter, wherein charging the second internalbattery comprises drawing current from the one or more adapter batteriesof the second charging adapter via the electrodes of the magneticconnection interface and the electrodes of the second charging adapter.

EXAMPLE 3

The system of example 2, further comprising a charging case, thecharging case comprising: one or more case batteries; and a housingcarrying the one or more case batteries, the housing comprising: a firstportion forming a first volume shaped to carry the first chargingadapter and the first earbud when the first charging adapter and thefirst earbud are attached; first electrodes arranged in the housing tocontact the electrodes of the first charging adapter when the firstcharging adapter is carried in the housing of the charging case, whereinthe one or more adapter batteries of the first charging adapter and thefirst internal battery of the first earbud charge from (a) the one ormore case batteries when the charging case is disconnected from wallpower or (b) wall power when the charging case is connected to wallpower, and wherein the first earbud draws current via the electrodes ofthe magnetic connection interface and the electrodes of the firstcharging adapter; a second portion forming a second volume shaped tocarry the second charging adapter and the second earbud when the secondcharging adapter and the second earbud are attached; and secondelectrodes arranged in the housing to contact the electrodes of thesecond charging adapter when the second charging adapter is carried inthe housing of the charging case, wherein the one or more adapterbatteries of the second charging adapter and the second internal batteryof the second earbud charge from (a) the one or more case batteries whenthe charging case is disconnected from wall power or (b) wall power whenthe charging case is connected to wall power, and wherein the secondearbud draws current via the electrodes of the magnetic connectioninterface and the electrodes of the second charging adapter.

EXAMPLE 4

The system of example 3, further comprising: a third charging adaptersubstantially similar to the first charging adapter; and a fourthcharging adapter substantially similar to the second charging adapter,wherein the housing of the charging case further comprises: a thirdportion forming a third volume shaped to carry the third chargingadapter; third electrodes arranged in the housing to contact electrodesof the third charging adapter when the third charging adapter is carriedin the housing of the charging case, wherein one or more adapterbatteries of the third charging adapter charge from (a) the one or morecase batteries when the charging case is disconnected from wall power or(b) wall power when the charging case is connected to wall power; afourth portion forming a fourth volume shaped to carry the fourthcharging adapter; and fourth electrodes arranged in the housing tocontact electrodes of the fourth charging adapter when the fourthcharging adapter is carried in the housing of the charging case, whereinone or more adapter batteries of the fourth charging adapter charge from(a) the one or more case batteries when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power.

EXAMPLE 5

The system of example 3, wherein the charging case further comprises (i)one or more coils, wherein a wireless charger induces a current in theone or more coils to wirelessly charge the one or more case batteriesfrom wall power connected to the wireless charger and (ii) a cable port,wherein a cable connected between the cable port and a wall chargerdelivers current to charge the one or more case batteries from wallpower connected to the wall charger.

EXAMPLE 6

The system of example 2, further comprising a charging case, thecharging case comprising: one or more case batteries; and a housingcarrying the one or more case batteries, the housing comprising: a firstportion forming a first volume shaped to carry the first earbud; firstelectrodes arranged in the housing to contact the electrodes of thefirst earbud when the first earbud is carried in the housing of thecharging case, wherein the first internal battery of the first earbudcharges from (a) the one or more case batteries when the charging caseis disconnected from wall power or (b) wall power when the charging caseis connected to wall power; a second portion forming a second volumeshaped to carry the first charging adapter; and second electrodesarranged in the housing to contact the electrodes of the first chargingadapter when the first charging adapter is carried in the housing of thecharging case, wherein the one or more adapter batteries of the firstcharging adapter charge from (a) the one or more case batteries when thecharging case is disconnected from wall power or (b) wall power when thecharging case is connected to wall power; a third portion forming athird volume shaped to carry the second earbud; third electrodesarranged in the housing to contact the electrodes of the second earbudwhen second earbud is carried in the housing of the charging case,wherein the second internal battery of the second earbud charges from(a) the one or more case batteries when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power; a fourth portion forming a fourth volume shapedto carry the second charging adapter; and fourth electrodes arranged inthe housing to contact the electrodes of the second charging adapterwhen the second charging adapter is carried in the housing of thecharging case, wherein the one or more adapter batteries of the secondcharging adapter charge from (a) the one or more case batteries when thecharging case is disconnected from wall power or (b) wall power when thecharging case is connected to wall power.

EXAMPLE 7

The system of example 5, further comprising: a third charging adaptersubstantially similar to the first charging adapter; and a fourthcharging adapter substantially similar to the second charging adapter,wherein the housing of the charging case further comprises: a fifthportion forming a fifth volume shaped to carry the third chargingadapter; fifth electrodes arranged in the housing to contact electrodesof the third charging adapter when the third charging adapter is carriedin the housing of the charging case, wherein one or more adapterbatteries of the third charging adapter charge from (a) the one or morecase batteries when the charging case is disconnected from wall power or(b) wall power when the charging case is connected to wall power; asixth portion forming a sixth volume shaped to carry the fourth chargingadapter; and sixth electrodes arranged in the housing to contactelectrodes of the fourth charging adapter when the fourth chargingadapter is carried in the housing of the charging case, wherein one ormore adapter batteries of the fourth charging adapter charge from (a)the one or more case batteries when the charging case is disconnectedfrom wall power or (b) wall power when the charging case is connected towall power.

EXAMPLE 8

The system of example 2, wherein the first charging adapter and thesecond charging adapter are interchangeable between the first earbud andthe second earbud.

EXAMPLE 9

The system of example 8, wherein the housings of the first chargingadapter and the second charging adapter are substantially coin-shaped

EXAMPLE 10

The system of example 2, wherein the first internal battery of the firstearbud and the second internal battery of the second earbud areremoveable, wherein the first charging adapter is swappable with thefirst internal battery, and wherein the second charging adapter isswappable with the second internal battery.

EXAMPLE 11

The system of example 1, wherein the system further comprises wirelessheadphones, the wireless headphones comprising: a third IEEE802.15-compatible interface; a third internal battery; two or more thirdaudio drivers; a housing carrying the first IEEE 802.15-compatibleinterface and the first internal battery, wherein the housing of thewireless headphones comprises: a first portion carrying a magneticinterface that includes one or more magnets that (i) attach the firstcharging adapter externally to the housing of the wireless headphonesand (ii) align electrodes of the first charging adapter to electrodes ofthe magnetic interface.

EXAMPLE 12

A first charging adapter comprising: one or more adapter batteries; anda housing carrying the one or more adapter batteries and a magneticinterface that includes one or more magnets that (i) attach the firstcharging adapter externally to a housing of a first earbud and (ii)align electrodes of the first charging adapter to electrodes of thefirst earbud, wherein a first internal battery of the first earbudcharges from the first charging adapter when the first charging adapteris attached to the housing of the first earbud via the magneticinterface, wherein the first earbud draws current from the one or moreadapter batteries of the first charging adapter via the electrodes ofthe magnetic connection interface and the electrodes of the firstearbud.

EXAMPLE 13

The first charging adapter of example 12, wherein the housing of thefirst charging adapter is formed to be carried within a volume in ahousing of a charging case, wherein the electrodes of the first chargingadapter contact first electrodes arranged in the housing of the chargingcase when the first charging adapter is carried in the housing of thecharging case, and wherein the one or more adapter batteries of thefirst charging adapter and the first internal battery of the firstearbud charge from (a) one or more case batteries of the charging casewhen the charging case is disconnected from wall power or (b) wall powerwhen the charging case is connected to wall power, and wherein the firstearbud draws current via the electrodes of the magnetic connectioninterface and the electrodes of the first earbud.

EXAMPLE 14

The first charging adapter of example 12, wherein the housing of thefirst charging adapter is formed to be carried within a volume in ahousing of a charging case, wherein the electrodes of the first chargingadapter contact first electrodes arranged in the housing of the chargingcase when the first charging adapter is carried in the housing of thecharging case, and wherein the one or more adapter batteries of thefirst charging adapter charge from (a) one or more case batteries of thecharging case when the charging case is disconnected from wall power or(b) wall power when the charging case is connected to wall power, andwherein the first charging adapter draws current via the electrodes ofthe magnetic interface and the first electrodes arranged in the housingof the charging case.

EXAMPLE 15

The first charging adapter of example 12, wherein the housing of thefirst charging adapter is substantially coin-shaped.

EXAMPLE 16

The first charging adapter of example 12, wherein the first internalbattery of the first earbud is removeable, and wherein the firstcharging adapter is swappable with the first internal battery.

EXAMPLE 17

A pair of wireless earbuds comprising a first earbud and a secondearbud, the first earbud comprising: a first IEEE 802.15-compatibleinterface; a first internal battery; a first audio driver; a housingcarrying the first IEEE 802.15-compatible interface and the firstinternal battery, wherein the housing of the first earbud comprises: afirst portion insertable into a first ear canal, the first portioncarrying the first audio driver; and a second portion carrying amagnetic interface that includes one or more magnets that (i) attach afirst charging adapter externally to the housing of the first earbud and(ii) align electrodes of the first charging adapter to electrodes of themagnetic interface; and a first controller carried in the housing of thefirst earbud and configured to perform functions comprising: detectingattachment of the first charging adapter to the magnetic interface; andbased on detecting that the first charging adapter is attached to themagnetic interface, causing the first internal battery to charge fromthe first charging adapter, wherein charging the first internal batterycomprises drawing current from one or more adapter batteries of thefirst charging adapter via the electrodes of the magnetic connectioninterface and the electrodes of the first charging adapter; and thesecond earbud comprising: a second IEEE 802.15-compatible interface; asecond internal battery; a second audio driver; a housing carrying thesecond IEEE 802.15-compatible interface and the second internal battery,wherein the housing of the second earbud comprises: a first portioninsertable into a second ear canal, the first portion carrying thesecond audio driver; and a second portion carrying a magnetic interfacethat includes one or more magnets that (i) attach a second chargingadapter externally to the housing of the second earbud and (ii) alignelectrodes of the second charging adapter to electrodes of the magneticinterface; a second controller carried in the housing of the secondearbud and configured to perform functions comprising: detectingattachment of the second charging adapter to the magnetic interface; andbased on detecting that the second charging adapter is attached to themagnetic interface, causing the second internal battery to charge fromthe second charging adapter, wherein charging the second internalbattery comprises drawing current from one or more adapter batteries ofthe second charging adapter via the electrodes of the magneticconnection interface and the electrodes of the second charging adapter.

EXAMPLE 18

The pair of wireless earbuds of example 17, wherein: the housing of thefirst earbud is formed to be carried within a first volume in a housingof a charging case while attached to the first charging adapter, whereinthe electrodes of the first charging adapter contact first electrodesarranged in the housing of the charging case when the first chargingadapter is carried in the housing of the charging case, and wherein theone or more adapter batteries of the first charging adapter and thefirst internal battery of the first earbud charge from (a) one or morecase batteries of the charging case when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power, and wherein the first earbud draws current viathe electrodes of the magnetic connection interface and the electrodesof the first charging adapter; and the housing of the second earbud isformed to be carried within a second volume in the housing of thecharging case while attached to the second charging adapter, wherein theelectrodes of the second charging adapter contact second electrodesarranged in the housing of the charging case when the second chargingadapter is carried in the housing of the charging case, and wherein theone or more adapter batteries of the second charging adapter and thesecond internal battery of the second earbud charge from (a) the one ormore case batteries of the charging case when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power, and wherein the second earbud draws current viathe electrodes of the magnetic connection interface and the electrodesof the second charging adapter.

EXAMPLE 19

The pair of wireless earbuds of example 17, wherein: the housing of thefirst earbud is formed to be carried within a first volume in a housingof a charging case while attached to the first charging adapter, whereinthe electrodes of the first charging adapter contact first electrodesarranged in the housing of the charging case when the first chargingadapter is carried in the housing of the charging case, and wherein theone or more adapter batteries of the first charging adapter and thefirst internal battery of the first earbud charge from (a) one or morecase batteries of the charging case when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power, and wherein the first earbud draws current viathe electrodes of the magnetic connection interface and the electrodesof the first charging adapter; and the housing of the second earbud isformed to be carried within a second volume in the housing of thecharging case while attached to the second charging adapter, wherein theelectrodes of the second charging adapter contact second electrodesarranged in the housing of the charging case when the second chargingadapter is carried in the housing of the charging case, and wherein theone or more adapter batteries of the second charging adapter and thesecond internal battery of the second earbud charge from (a) the one ormore case batteries of the charging case when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power, and wherein the second earbud draws current viathe electrodes of the magnetic connection interface and the electrodesof the second charging adapter.

EXAMPLE 20

The pair of wireless earbuds of example 17, wherein the first chargingadapter and the second charging adapter are interchangeable between thefirst earbud and the second earbud.

EXAMPLE 21

The pair of wireless earbuds of example 17, wherein the first internalbattery of the first earbud and the second internal battery of thesecond earbud are removeable, wherein the first charging adapter isswappable with the first internal battery, and wherein the secondcharging adapter is swappable with the second internal battery.

EXAMPLE 22

A charging case comprising: one or more case batteries; and a housingcarrying the one or more case batteries, the housing comprising: a firstportion forming a first volume shaped to carry a first charging adapterand a first earbud when the first charging adapter and the first earbudare attached; first electrodes arranged in the housing to contactelectrodes of the first charging adapter when the first charging adapteris carried in the housing of the charging case, wherein one or moreadapter batteries of the first charging adapter and a first internalbattery of the first earbud charge from (a) the one or more casebatteries when the charging case is disconnected from wall power or (b)wall power when the charging case is connected to wall power, andwherein the first earbud draws current via the electrodes of themagnetic connection interface and the electrodes of the first chargingadapter; a second portion forming a second volume shaped to carry asecond charging adapter and a second earbud when the second chargingadapter and the second earbud are attached; and second electrodesarranged in the housing to contact electrodes of the second chargingadapter when the second charging adapter is carried in the housing ofthe charging case, wherein one or more adapter batteries of the secondcharging adapter and a second internal battery of the second earbudcharge from (a) the one or more case batteries when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power, and wherein the second earbud draws current viathe electrodes of the magnetic connection interface and the electrodesof the second charging adapter.

EXAMPLE 23

The charging case of example 22, further comprising: a third portionforming a third volume shaped to carry a third charging adapter; thirdelectrodes arranged in the housing to contact electrodes of the thirdcharging adapter when the third charging adapter is carried in thehousing of the charging case, wherein one or more adapter batteries ofthe third charging adapter charge from (a) the one or more casebatteries when the charging case is disconnected from wall power or (b)wall power when the charging case is connected to wall power; a fourthportion forming a fourth volume shaped to carry a fourth chargingadapter; and fourth electrodes arranged in the housing to contactelectrodes of the fourth charging adapter when the fourth chargingadapter is carried in the housing of the charging case, wherein one ormore adapter batteries of the fourth charging adapter charge from (a)the one or more case batteries when the charging case is disconnectedfrom wall power or (b) wall power when the charging case is connected towall power.

EXAMPLE 24

The charging case of example 22, wherein the charging case furthercomprises (i) one or more coils, wherein a wireless charger induces acurrent in the one or more coils to wirelessly charge the one or morecase batteries from wall power connected to the wireless charger and(ii) a cable port, wherein a cable connected between the cable port anda wall charger delivers current to charge the one or more case batteriesfrom wall power connected to the wall charger.

We claim:
 1. A system comprising: a first charging adapter comprisingone or more adapter batteries; and a first earbud, the first earbudcomprising: a first IEEE 802.15-compatible interface; a first internalbattery; a first audio driver; a housing carrying the first IEEE802.15-compatible interface and the first internal battery, wherein thehousing of the first earbud comprises: a first portion insertable into afirst ear canal, the first portion carrying the first audio driver; anda second portion carrying a magnetic interface that includes one or moremagnets that (i) attach the first charging adapter externally to thehousing of the first earbud and (ii) align electrodes of the firstcharging adapter to electrodes of the magnetic interface; and a firstcontroller carried in the housing of the first earbud and configured toperform functions comprising: detecting attachment of the first chargingadapter to the magnetic interface; and based on detecting that the firstcharging adapter is attached to the magnetic interface, causing thefirst internal battery to charge from the first charging adapter,wherein charging the first internal battery comprises drawing currentfrom the one or more adapter batteries of the first charging adapter viathe electrodes of the magnetic connection interface and the electrodesof the first charging adapter.
 2. The system of claim 1, furthercomprising: a second charging adapter comprising one or more adapterbatteries; and a second earbud, the second earbud comprising: a secondIEEE 802.15-compatible interface; a second internal battery; a secondaudio driver; a housing carrying the second IEEE 802.15-compatibleinterface and the second internal battery, wherein the housing of thesecond earbud comprises: a first portion insertable into a second earcanal, the first portion carrying the second audio driver; and a secondportion carrying a magnetic interface that includes one or more magnetsthat (i) attach the second charging adapter externally to the housing ofthe second earbud and (ii) align electrodes of the second chargingadapter to electrodes of the magnetic interface; a second controllercarried in the housing of the second earbud and configured to performfunctions comprising: detecting attachment of the second chargingadapter to the magnetic interface; and based on detecting that thesecond charging adapter is attached to the magnetic interface, causingthe second internal battery to charge from the second charging adapter,wherein charging the second internal battery comprises drawing currentfrom the one or more adapter batteries of the second charging adaptervia the electrodes of the magnetic connection interface and theelectrodes of the second charging adapter.
 3. The system of claim 2,further comprising a charging case, the charging case comprising: one ormore case batteries; and a housing carrying the one or more casebatteries, the housing comprising: a first portion forming a firstvolume shaped to carry the first charging adapter and the first earbudwhen the first charging adapter and the first earbud are attached; firstelectrodes arranged in the housing to contact the electrodes of thefirst charging adapter when the first charging adapter is carried in thehousing of the charging case, wherein the one or more adapter batteriesof the first charging adapter and the first internal battery of thefirst earbud charge from (a) the one or more case batteries when thecharging case is disconnected from wall power or (b) wall power when thecharging case is connected to wall power, and wherein the first earbuddraws current via the electrodes of the magnetic connection interfaceand the electrodes of the first charging adapter; a second portionforming a second volume shaped to carry the second charging adapter andthe second earbud when the second charging adapter and the second earbudare attached; and second electrodes arranged in the housing to contactthe electrodes of the second charging adapter when the second chargingadapter is carried in the housing of the charging case, wherein the oneor more adapter batteries of the second charging adapter and the secondinternal battery of the second earbud charge from (a) the one or morecase batteries when the charging case is disconnected from wall power or(b) wall power when the charging case is connected to wall power, andwherein the second earbud draws current via the electrodes of themagnetic connection interface and the electrodes of the second chargingadapter.
 4. The system of claim 3, further comprising: a third chargingadapter substantially similar to the first charging adapter; and afourth charging adapter substantially similar to the second chargingadapter, wherein the housing of the charging case further comprises: athird portion forming a third volume shaped to carry the third chargingadapter; third electrodes arranged in the housing to contact electrodesof the third charging adapter when the third charging adapter is carriedin the housing of the charging case, wherein one or more adapterbatteries of the third charging adapter charge from (a) the one or morecase batteries when the charging case is disconnected from wall power or(b) wall power when the charging case is connected to wall power; afourth portion forming a fourth volume shaped to carry the fourthcharging adapter; and fourth electrodes arranged in the housing tocontact electrodes of the fourth charging adapter when the fourthcharging adapter is carried in the housing of the charging case, whereinone or more adapter batteries of the fourth charging adapter charge from(a) the one or more case batteries when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power.
 5. The system of claim 3, wherein the chargingcase further comprises (i) one or more coils, wherein a wireless chargerinduces a current in the one or more coils to wirelessly charge the oneor more case batteries from wall power connected to the wireless chargerand (ii) a cable port, wherein a cable connected between the cable portand a wall charger delivers current to charge the one or more casebatteries from wall power connected to the wall charger.
 6. The systemof claim 2, further comprising a charging case, the charging casecomprising: one or more case batteries; and a housing carrying the oneor more case batteries, the housing comprising: a first portion forminga first volume shaped to carry the first earbud; first electrodesarranged in the housing to contact the electrodes of the first earbudwhen the first earbud is carried in the housing of the charging case,wherein the first internal battery of the first earbud charges from (a)the one or more case batteries when the charging case is disconnectedfrom wall power or (b) wall power when the charging case is connected towall power; a second portion forming a second volume shaped to carry thefirst charging adapter; and second electrodes arranged in the housing tocontact the electrodes of the first charging adapter when the firstcharging adapter is carried in the housing of the charging case, whereinthe one or more adapter batteries of the first charging adapter chargefrom (a) the one or more case batteries when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power; a third portion forming a third volume shapedto carry the second earbud; third electrodes arranged in the housing tocontact the electrodes of the second earbud when second earbud iscarried in the housing of the charging case, wherein the second internalbattery of the second earbud charges from (a) the one or more casebatteries when the charging case is disconnected from wall power or (b)wall power when the charging case is connected to wall power; a fourthportion forming a fourth volume shaped to carry the second chargingadapter; and fourth electrodes arranged in the housing to contact theelectrodes of the second charging adapter when the second chargingadapter is carried in the housing of the charging case, wherein the oneor more adapter batteries of the second charging adapter charge from (a)the one or more case batteries when the charging case is disconnectedfrom wall power or (b) wall power when the charging case is connected towall power.
 7. The system of claim 5, further comprising: a thirdcharging adapter substantially similar to the first charging adapter;and a fourth charging adapter substantially similar to the secondcharging adapter, wherein the housing of the charging case furthercomprises: a fifth portion forming a fifth volume shaped to carry thethird charging adapter; fifth electrodes arranged in the housing tocontact electrodes of the third charging adapter when the third chargingadapter is carried in the housing of the charging case, wherein one ormore adapter batteries of the third charging adapter charge from (a) theone or more case batteries when the charging case is disconnected fromwall power or (b) wall power when the charging case is connected to wallpower; a sixth portion forming a sixth volume shaped to carry the fourthcharging adapter; and sixth electrodes arranged in the housing tocontact electrodes of the fourth charging adapter when the fourthcharging adapter is carried in the housing of the charging case, whereinone or more adapter batteries of the fourth charging adapter charge from(a) the one or more case batteries when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power.
 8. The system of claim 2, wherein the firstcharging adapter and the second charging adapter are interchangeablebetween the first earbud and the second earbud.
 9. The system of claim8, wherein the housings of the first charging adapter and the secondcharging adapter are substantially coin-shaped.
 10. The system of claim2, wherein the first internal battery of the first earbud and the secondinternal battery of the second earbud are removeable, wherein the firstcharging adapter is swappable with the first internal battery, andwherein the second charging adapter is swappable with the secondinternal battery.
 11. The system of claim 1, wherein the system furthercomprises wireless headphones, the wireless headphones comprising: athird IEEE 802.15-compatible interface; a third internal battery; two ormore third audio drivers; a housing carrying the first IEEE802.15-compatible interface and the first internal battery, wherein thehousing of the wireless headphones comprises: a first portion carrying amagnetic interface that includes one or more magnets that (i) attach thefirst charging adapter externally to the housing of the wirelessheadphones and (ii) align electrodes of the first charging adapter toelectrodes of the magnetic interface.
 12. A first charging adaptercomprising: one or more adapter batteries; and a housing carrying theone or more adapter batteries and a magnetic interface that includes oneor more magnets that (i) attach the first charging adapter externally toa housing of a first earbud and (ii) align electrodes of the firstcharging adapter to electrodes of the first earbud, wherein a firstinternal battery of the first earbud charges from the first chargingadapter when the first charging adapter is attached to the housing ofthe first earbud via the magnetic interface, wherein the first earbuddraws current from the one or more adapter batteries of the firstcharging adapter via the electrodes of the magnetic connection interfaceand the electrodes of the first earbud.
 13. The first charging adapterof claim 12, wherein the housing of the first charging adapter is formedto be carried within a volume in a housing of a charging case, whereinthe electrodes of the first charging adapter contact first electrodesarranged in the housing of the charging case when the first chargingadapter is carried in the housing of the charging case, and wherein theone or more adapter batteries of the first charging adapter and thefirst internal battery of the first earbud charge from (a) one or morecase batteries of the charging case when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power, and wherein the first earbud draws current viathe electrodes of the magnetic connection interface and the electrodesof the first earbud.
 14. The first charging adapter of claim 12, whereinthe housing of the first charging adapter is formed to be carried withina volume in a housing of a charging case, wherein the electrodes of thefirst charging adapter contact first electrodes arranged in the housingof the charging case when the first charging adapter is carried in thehousing of the charging case, and wherein the one or more adapterbatteries of the first charging adapter charge from (a) one or more casebatteries of the charging case when the charging case is disconnectedfrom wall power or (b) wall power when the charging case is connected towall power, and wherein the first charging adapter draws current via theelectrodes of the magnetic interface and the first electrodes arrangedin the housing of the charging case.
 15. The first charging adapter ofclaim 12, wherein the housing of the first charging adapter issubstantially coin-shaped.
 16. The first charging adapter of claim 12,wherein the first internal battery of the first earbud is removeable,and wherein the first charging adapter is swappable with the firstinternal battery.
 17. A pair of wireless earbuds comprising a firstearbud and a second earbud, the first earbud comprising: a first IEEE802.15-compatible interface; a first internal battery; a first audiodriver; a housing carrying the first IEEE 802.15-compatible interfaceand the first internal battery, wherein the housing of the first earbudcomprises: a first portion insertable into a first ear canal, the firstportion carrying the first audio driver; and a second portion carrying amagnetic interface that includes one or more magnets that (i) attach afirst charging adapter externally to the housing of the first earbud and(ii) align electrodes of the first charging adapter to electrodes of themagnetic interface; and a first controller carried in the housing of thefirst earbud and configured to perform functions comprising: detectingattachment of the first charging adapter to the magnetic interface; andbased on detecting that the first charging adapter is attached to themagnetic interface, causing the first internal battery to charge fromthe first charging adapter, wherein charging the first internal batterycomprises drawing current from one or more adapter batteries of thefirst charging adapter via the electrodes of the magnetic connectioninterface and the electrodes of the first charging adapter; and thesecond earbud comprising: a second IEEE 802.15-compatible interface; asecond internal battery; a second audio driver; a housing carrying thesecond IEEE 802.15-compatible interface and the second internal battery,wherein the housing of the second earbud comprises: a first portioninsertable into a second ear canal, the first portion carrying thesecond audio driver; and a second portion carrying a magnetic interfacethat includes one or more magnets that (i) attach a second chargingadapter externally to the housing of the second earbud and (ii) alignelectrodes of the second charging adapter to electrodes of the magneticinterface; a second controller carried in the housing of the secondearbud and configured to perform functions comprising: detectingattachment of the second charging adapter to the magnetic interface; andbased on detecting that the second charging adapter is attached to themagnetic interface, causing the second internal battery to charge fromthe second charging adapter, wherein charging the second internalbattery comprises drawing current from one or more adapter batteries ofthe second charging adapter via the electrodes of the magneticconnection interface and the electrodes of the second charging adapter.18. The pair of wireless earbuds of claim 17, wherein: the housing ofthe first earbud is formed to be carried within a first volume in ahousing of a charging case while attached to the first charging adapter,wherein the electrodes of the first charging adapter contact firstelectrodes arranged in the housing of the charging case when the firstcharging adapter is carried in the housing of the charging case, andwherein the one or more adapter batteries of the first charging adapterand the first internal battery of the first earbud charge from (a) oneor more case batteries of the charging case when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power, and wherein the first earbud draws current viathe electrodes of the magnetic connection interface and the electrodesof the first charging adapter; and the housing of the second earbud isformed to be carried within a second volume in the housing of thecharging case while attached to the second charging adapter, wherein theelectrodes of the second charging adapter contact second electrodesarranged in the housing of the charging case when the second chargingadapter is carried in the housing of the charging case, and wherein theone or more adapter batteries of the second charging adapter and thesecond internal battery of the second earbud charge from (a) the one ormore case batteries of the charging case when the charging case isdisconnected from wall power or (b) wall power when the charging case isconnected to wall power, and wherein the second earbud draws current viathe electrodes of the magnetic connection interface and the electrodesof the second charging adapter.
 19. The pair of wireless earbuds ofclaim 17, wherein: the housing of the first earbud is formed to becarried within a first volume in a housing of a charging case whileattached to the first charging adapter, wherein the electrodes of thefirst charging adapter contact first electrodes arranged in the housingof the charging case when the first charging adapter is carried in thehousing of the charging case, and wherein the one or more adapterbatteries of the first charging adapter and the first internal batteryof the first earbud charge from (a) one or more case batteries of thecharging case when the charging case is disconnected from wall power or(b) wall power when the charging case is connected to wall power, andwherein the first earbud draws current via the electrodes of themagnetic connection interface and the electrodes of the first chargingadapter; and the housing of the second earbud is formed to be carriedwithin a second volume in the housing of the charging case whileattached to the second charging adapter, wherein the electrodes of thesecond charging adapter contact second electrodes arranged in thehousing of the charging case when the second charging adapter is carriedin the housing of the charging case, and wherein the one or more adapterbatteries of the second charging adapter and the second internal batteryof the second earbud charge from (a) the one or more case batteries ofthe charging case when the charging case is disconnected from wall poweror (b) wall power when the charging case is connected to wall power, andwherein the second earbud draws current via the electrodes of themagnetic connection interface and the electrodes of the second chargingadapter.
 20. The pair of wireless earbuds of claim 17, wherein the firstcharging adapter and the second charging adapter are interchangeablebetween the first earbud and the second earbud.
 21. The pair of wirelessearbuds of claim 17, wherein the first internal battery of the firstearbud and the second internal battery of the second earbud areremoveable, wherein the first charging adapter is swappable with thefirst internal battery, and wherein the second charging adapter isswappable with the second internal battery.
 22. A charging casecomprising: one or more case batteries; and a housing carrying the oneor more case batteries, the housing comprising: a first portion forminga first volume shaped to carry a first charging adapter and a firstearbud when the first charging adapter and the first earbud areattached; first electrodes arranged in the housing to contact electrodesof the first charging adapter when the first charging adapter is carriedin the housing of the charging case, wherein one or more adapterbatteries of the first charging adapter and a first internal battery ofthe first earbud charge from (a) the one or more case batteries when thecharging case is disconnected from wall power or (b) wall power when thecharging case is connected to wall power, and wherein the first earbuddraws current via the electrodes of the magnetic connection interfaceand the electrodes of the first charging adapter; a second portionforming a second volume shaped to carry a second charging adapter and asecond earbud when the second charging adapter and the second earbud areattached; and second electrodes arranged in the housing to contactelectrodes of the second charging adapter when the second chargingadapter is carried in the housing of the charging case, wherein one ormore adapter batteries of the second charging adapter and a secondinternal battery of the second earbud charge from (a) the one or morecase batteries when the charging case is disconnected from wall power or(b) wall power when the charging case is connected to wall power, andwherein the second earbud draws current via the electrodes of themagnetic connection interface and the electrodes of the second chargingadapter.
 23. The charging case of claim 22, further comprising: a thirdportion forming a third volume shaped to carry a third charging adapter;third electrodes arranged in the housing to contact electrodes of thethird charging adapter when the third charging adapter is carried in thehousing of the charging case, wherein one or more adapter batteries ofthe third charging adapter charge from (a) the one or more casebatteries when the charging case is disconnected from wall power or (b)wall power when the charging case is connected to wall power; a fourthportion forming a fourth volume shaped to carry a fourth chargingadapter; and fourth electrodes arranged in the housing to contactelectrodes of the fourth charging adapter when the fourth chargingadapter is carried in the housing of the charging case, wherein one ormore adapter batteries of the fourth charging adapter charge from (a)the one or more case batteries when the charging case is disconnectedfrom wall power or (b) wall power when the charging case is connected towall power.
 24. The charging case of claim 22, wherein the charging casefurther comprises (i) one or more coils, wherein a wireless chargerinduces a current in the one or more coils to wirelessly charge the oneor more case batteries from wall power connected to the wireless chargerand (ii) a cable port, wherein a cable connected between the cable portand a wall charger delivers current to charge the one or more casebatteries from wall power connected to the wall charger.